diff --git a/head/schema-cjson/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.c b/head/schema-cjson/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.c
new file mode 100644
index 0000000..5284248
--- /dev/null
+++ b/head/schema-cjson/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.c
@@ -0,0 +1,393 @@
+/**
+ * TopLevel.c
+ * This file has been autogenerated using quicktype https://github.com/quicktype/quicktype - DO NOT EDIT
+ */
+
+#include "TopLevel.h"
+
+enum Status cJSON_GetStatusValue(const cJSON * j) {
+    enum Status x = 0;
+    if (NULL != j) {
+        if (!strcmp(cJSON_GetStringValue(j), "ready")) x = STATUS_READY;
+        else if (!strcmp(cJSON_GetStringValue(j), "done")) x = STATUS_DONE;
+    }
+    return x;
+}
+
+cJSON * cJSON_CreateStatus(const enum Status x) {
+    cJSON * j = NULL;
+    switch (x) {
+        case STATUS_READY: j = cJSON_CreateString("ready"); break;
+        case STATUS_DONE: j = cJSON_CreateString("done"); break;
+    }
+    return j;
+}
+
+struct DateTime * cJSON_ParseDateTime(const char * s) {
+    struct DateTime * x = NULL;
+    if (NULL != s) {
+        cJSON * j = cJSON_Parse(s);
+        if (NULL != j) {
+            x = cJSON_GetDateTimeValue(j);
+            cJSON_Delete(j);
+        }
+    }
+    return x;
+}
+
+struct DateTime * cJSON_GetDateTimeValue(const cJSON * j) {
+    struct DateTime * x = NULL;
+    if (NULL != j) {
+        if (NULL != (x = cJSON_malloc(sizeof(struct DateTime)))) {
+            memset(x, 0, sizeof(struct DateTime));
+            if (!cJSON_HasObjectItem(j, "value")) { cJSON_DeleteDateTime(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "value")) {
+                if (!quicktype_cJSON_IsInteger(cJSON_GetObjectItemCaseSensitive(j, "value"))) { cJSON_DeleteDateTime(x); return NULL; }
+                x->value = cJSON_GetNumberValue(cJSON_GetObjectItemCaseSensitive(j, "value"));
+            }
+        }
+    }
+    return x;
+}
+
+cJSON * cJSON_CreateDateTime(const struct DateTime * x) {
+    cJSON * j = NULL;
+    if (NULL != x) {
+        if (NULL != (j = cJSON_CreateObject())) {
+            cJSON_AddNumberToObject(j, "value", x->value);
+        }
+    }
+    return j;
+}
+
+char * cJSON_PrintDateTime(const struct DateTime * x) {
+    char * s = NULL;
+    if (NULL != x) {
+        cJSON * j = cJSON_CreateDateTime(x);
+        if (NULL != j) {
+            s = cJSON_Print(j);
+            cJSON_Delete(j);
+        }
+    }
+    return s;
+}
+
+void cJSON_DeleteDateTime(struct DateTime * x) {
+    if (NULL != x) {
+        cJSON_free(x);
+    }
+}
+
+struct EnumValues * cJSON_ParseEnumValues(const char * s) {
+    struct EnumValues * x = NULL;
+    if (NULL != s) {
+        cJSON * j = cJSON_Parse(s);
+        if (NULL != j) {
+            x = cJSON_GetEnumValuesValue(j);
+            cJSON_Delete(j);
+        }
+    }
+    return x;
+}
+
+struct EnumValues * cJSON_GetEnumValuesValue(const cJSON * j) {
+    struct EnumValues * x = NULL;
+    if (NULL != j) {
+        if (NULL != (x = cJSON_malloc(sizeof(struct EnumValues)))) {
+            memset(x, 0, sizeof(struct EnumValues));
+            if (!cJSON_HasObjectItem(j, "label")) { cJSON_DeleteEnumValues(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "label")) {
+                if (!cJSON_IsString(cJSON_GetObjectItemCaseSensitive(j, "label"))) { cJSON_DeleteEnumValues(x); return NULL; }
+                x->label = strdup(cJSON_GetStringValue(cJSON_GetObjectItemCaseSensitive(j, "label")));
+            }
+            else {
+                if (NULL != (x->label = cJSON_malloc(sizeof(char)))) {
+                    x->label[0] = '\0';
+                }
+            }
+        }
+    }
+    return x;
+}
+
+cJSON * cJSON_CreateEnumValues(const struct EnumValues * x) {
+    cJSON * j = NULL;
+    if (NULL != x) {
+        if (NULL != (j = cJSON_CreateObject())) {
+            if (NULL != x->label) {
+                cJSON_AddStringToObject(j, "label", x->label);
+            }
+            else {
+                cJSON_AddStringToObject(j, "label", "");
+            }
+        }
+    }
+    return j;
+}
+
+char * cJSON_PrintEnumValues(const struct EnumValues * x) {
+    char * s = NULL;
+    if (NULL != x) {
+        cJSON * j = cJSON_CreateEnumValues(x);
+        if (NULL != j) {
+            s = cJSON_Print(j);
+            cJSON_Delete(j);
+        }
+    }
+    return s;
+}
+
+void cJSON_DeleteEnumValues(struct EnumValues * x) {
+    if (NULL != x) {
+        if (NULL != x->label) {
+            cJSON_free(x->label);
+        }
+        cJSON_free(x);
+    }
+}
+
+struct FormatException * cJSON_ParseFormatException(const char * s) {
+    struct FormatException * x = NULL;
+    if (NULL != s) {
+        cJSON * j = cJSON_Parse(s);
+        if (NULL != j) {
+            x = cJSON_GetFormatExceptionValue(j);
+            cJSON_Delete(j);
+        }
+    }
+    return x;
+}
+
+struct FormatException * cJSON_GetFormatExceptionValue(const cJSON * j) {
+    struct FormatException * x = NULL;
+    if (NULL != j) {
+        if (NULL != (x = cJSON_malloc(sizeof(struct FormatException)))) {
+            memset(x, 0, sizeof(struct FormatException));
+            if (!cJSON_HasObjectItem(j, "count")) { cJSON_DeleteFormatException(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "count")) {
+                if (!quicktype_cJSON_IsInteger(cJSON_GetObjectItemCaseSensitive(j, "count"))) { cJSON_DeleteFormatException(x); return NULL; }
+                x->count = cJSON_GetNumberValue(cJSON_GetObjectItemCaseSensitive(j, "count"));
+            }
+        }
+    }
+    return x;
+}
+
+cJSON * cJSON_CreateFormatException(const struct FormatException * x) {
+    cJSON * j = NULL;
+    if (NULL != x) {
+        if (NULL != (j = cJSON_CreateObject())) {
+            cJSON_AddNumberToObject(j, "count", x->count);
+        }
+    }
+    return j;
+}
+
+char * cJSON_PrintFormatException(const struct FormatException * x) {
+    char * s = NULL;
+    if (NULL != x) {
+        cJSON * j = cJSON_CreateFormatException(x);
+        if (NULL != j) {
+            s = cJSON_Print(j);
+            cJSON_Delete(j);
+        }
+    }
+    return s;
+}
+
+void cJSON_DeleteFormatException(struct FormatException * x) {
+    if (NULL != x) {
+        cJSON_free(x);
+    }
+}
+
+struct RegExp * cJSON_ParseRegExp(const char * s) {
+    struct RegExp * x = NULL;
+    if (NULL != s) {
+        cJSON * j = cJSON_Parse(s);
+        if (NULL != j) {
+            x = cJSON_GetRegExpValue(j);
+            cJSON_Delete(j);
+        }
+    }
+    return x;
+}
+
+struct RegExp * cJSON_GetRegExpValue(const cJSON * j) {
+    struct RegExp * x = NULL;
+    if (NULL != j) {
+        if (NULL != (x = cJSON_malloc(sizeof(struct RegExp)))) {
+            memset(x, 0, sizeof(struct RegExp));
+            if (!cJSON_HasObjectItem(j, "active")) { cJSON_DeleteRegExp(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "active")) {
+                if (!cJSON_IsBool(cJSON_GetObjectItemCaseSensitive(j, "active"))) { cJSON_DeleteRegExp(x); return NULL; }
+                x->active = cJSON_IsTrue(cJSON_GetObjectItemCaseSensitive(j, "active"));
+            }
+        }
+    }
+    return x;
+}
+
+cJSON * cJSON_CreateRegExp(const struct RegExp * x) {
+    cJSON * j = NULL;
+    if (NULL != x) {
+        if (NULL != (j = cJSON_CreateObject())) {
+            cJSON_AddBoolToObject(j, "active", x->active);
+        }
+    }
+    return j;
+}
+
+char * cJSON_PrintRegExp(const struct RegExp * x) {
+    char * s = NULL;
+    if (NULL != x) {
+        cJSON * j = cJSON_CreateRegExp(x);
+        if (NULL != j) {
+            s = cJSON_Print(j);
+            cJSON_Delete(j);
+        }
+    }
+    return s;
+}
+
+void cJSON_DeleteRegExp(struct RegExp * x) {
+    if (NULL != x) {
+        cJSON_free(x);
+    }
+}
+
+struct TopLevel * cJSON_ParseTopLevel(const char * s) {
+    struct TopLevel * x = NULL;
+    if (NULL != s) {
+        cJSON * j = cJSON_Parse(s);
+        if (NULL != j) {
+            x = cJSON_GetTopLevelValue(j);
+            cJSON_Delete(j);
+        }
+    }
+    return x;
+}
+
+struct TopLevel * cJSON_GetTopLevelValue(const cJSON * j) {
+    struct TopLevel * x = NULL;
+    if (NULL != j) {
+        if (NULL != (x = cJSON_malloc(sizeof(struct TopLevel)))) {
+            memset(x, 0, sizeof(struct TopLevel));
+            if (!cJSON_HasObjectItem(j, "code")) { cJSON_DeleteTopLevel(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "code")) {
+                if (!cJSON_IsString(cJSON_GetObjectItemCaseSensitive(j, "code"))) { cJSON_DeleteTopLevel(x); return NULL; }
+                regex_t regex; regcomp(&regex, "^[a-z]+$", REG_EXTENDED); if (regexec(&regex, cJSON_GetObjectItemCaseSensitive(j, "code")->valuestring, 0, NULL, 0)) { regfree(&regex); cJSON_DeleteTopLevel(x); return NULL; } regfree(&regex);
+                if (strlen(cJSON_GetObjectItemCaseSensitive(j, "code")->valuestring) < 1) { cJSON_DeleteTopLevel(x); return NULL; }
+                x->code = strdup(cJSON_GetStringValue(cJSON_GetObjectItemCaseSensitive(j, "code")));
+            }
+            else {
+                if (NULL != (x->code = cJSON_malloc(sizeof(char)))) {
+                    x->code[0] = '\0';
+                }
+            }
+            if (!cJSON_HasObjectItem(j, "dateTime")) { cJSON_DeleteTopLevel(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "dateTime")) {
+                if (!cJSON_IsObject(cJSON_GetObjectItemCaseSensitive(j, "dateTime"))) { cJSON_DeleteTopLevel(x); return NULL; }
+                x->date_time = cJSON_GetDateTimeValue(cJSON_GetObjectItemCaseSensitive(j, "dateTime"));
+                if (NULL == x->date_time) { cJSON_DeleteTopLevel(x); return NULL; }
+            }
+            if (!cJSON_HasObjectItem(j, "enumValues")) { cJSON_DeleteTopLevel(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "enumValues")) {
+                if (!cJSON_IsObject(cJSON_GetObjectItemCaseSensitive(j, "enumValues"))) { cJSON_DeleteTopLevel(x); return NULL; }
+                x->enum_values = cJSON_GetEnumValuesValue(cJSON_GetObjectItemCaseSensitive(j, "enumValues"));
+                if (NULL == x->enum_values) { cJSON_DeleteTopLevel(x); return NULL; }
+            }
+            if (!cJSON_HasObjectItem(j, "formatException")) { cJSON_DeleteTopLevel(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "formatException")) {
+                if (!cJSON_IsObject(cJSON_GetObjectItemCaseSensitive(j, "formatException"))) { cJSON_DeleteTopLevel(x); return NULL; }
+                x->format_exception = cJSON_GetFormatExceptionValue(cJSON_GetObjectItemCaseSensitive(j, "formatException"));
+                if (NULL == x->format_exception) { cJSON_DeleteTopLevel(x); return NULL; }
+            }
+            if (!cJSON_HasObjectItem(j, "regExp")) { cJSON_DeleteTopLevel(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "regExp")) {
+                if (!cJSON_IsObject(cJSON_GetObjectItemCaseSensitive(j, "regExp"))) { cJSON_DeleteTopLevel(x); return NULL; }
+                x->reg_exp = cJSON_GetRegExpValue(cJSON_GetObjectItemCaseSensitive(j, "regExp"));
+                if (NULL == x->reg_exp) { cJSON_DeleteTopLevel(x); return NULL; }
+            }
+            if (!cJSON_HasObjectItem(j, "status")) { cJSON_DeleteTopLevel(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "status")) {
+                if (!cJSON_IsString(cJSON_GetObjectItemCaseSensitive(j, "status"))) { cJSON_DeleteTopLevel(x); return NULL; }
+                if (!cJSON_IsString(cJSON_GetObjectItemCaseSensitive(j, "status")) || 0 == cJSON_GetStatusValue(cJSON_GetObjectItemCaseSensitive(j, "status"))) { cJSON_DeleteTopLevel(x); return NULL; }
+                x->status = cJSON_GetStatusValue(cJSON_GetObjectItemCaseSensitive(j, "status"));
+            }
+            if (!cJSON_HasObjectItem(j, "timestamp")) { cJSON_DeleteTopLevel(x); return NULL; }
+            if (cJSON_HasObjectItem(j, "timestamp")) {
+                if (!cJSON_IsString(cJSON_GetObjectItemCaseSensitive(j, "timestamp"))) { cJSON_DeleteTopLevel(x); return NULL; }
+                x->timestamp = strdup(cJSON_GetStringValue(cJSON_GetObjectItemCaseSensitive(j, "timestamp")));
+            }
+            else {
+                if (NULL != (x->timestamp = cJSON_malloc(sizeof(char)))) {
+                    x->timestamp[0] = '\0';
+                }
+            }
+        }
+    }
+    return x;
+}
+
+cJSON * cJSON_CreateTopLevel(const struct TopLevel * x) {
+    cJSON * j = NULL;
+    if (NULL != x) {
+        if (NULL != (j = cJSON_CreateObject())) {
+            if (NULL != x->code) {
+                cJSON_AddStringToObject(j, "code", x->code);
+            }
+            else {
+                cJSON_AddStringToObject(j, "code", "");
+            }
+            cJSON_AddItemToObject(j, "dateTime", cJSON_CreateDateTime(x->date_time));
+            cJSON_AddItemToObject(j, "enumValues", cJSON_CreateEnumValues(x->enum_values));
+            cJSON_AddItemToObject(j, "formatException", cJSON_CreateFormatException(x->format_exception));
+            cJSON_AddItemToObject(j, "regExp", cJSON_CreateRegExp(x->reg_exp));
+            cJSON_AddItemToObject(j, "status", cJSON_CreateStatus(x->status));
+            if (NULL != x->timestamp) {
+                cJSON_AddStringToObject(j, "timestamp", x->timestamp);
+            }
+            else {
+                cJSON_AddStringToObject(j, "timestamp", "");
+            }
+        }
+    }
+    return j;
+}
+
+char * cJSON_PrintTopLevel(const struct TopLevel * x) {
+    char * s = NULL;
+    if (NULL != x) {
+        cJSON * j = cJSON_CreateTopLevel(x);
+        if (NULL != j) {
+            s = cJSON_Print(j);
+            cJSON_Delete(j);
+        }
+    }
+    return s;
+}
+
+void cJSON_DeleteTopLevel(struct TopLevel * x) {
+    if (NULL != x) {
+        if (NULL != x->code) {
+            cJSON_free(x->code);
+        }
+        if (NULL != x->date_time) {
+            cJSON_DeleteDateTime(x->date_time);
+        }
+        if (NULL != x->enum_values) {
+            cJSON_DeleteEnumValues(x->enum_values);
+        }
+        if (NULL != x->format_exception) {
+            cJSON_DeleteFormatException(x->format_exception);
+        }
+        if (NULL != x->reg_exp) {
+            cJSON_DeleteRegExp(x->reg_exp);
+        }
+        if (NULL != x->timestamp) {
+            cJSON_free(x->timestamp);
+        }
+        cJSON_free(x);
+    }
+}
diff --git a/head/schema-cjson/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.h b/head/schema-cjson/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.h
new file mode 100644
index 0000000..bca175d
--- /dev/null
+++ b/head/schema-cjson/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.h
@@ -0,0 +1,109 @@
+/**
+ * TopLevel.h
+ * This file has been autogenerated using quicktype https://github.com/quicktype/quicktype - DO NOT EDIT
+ * This file depends of https://github.com/DaveGamble/cJSON, https://github.com/joelguittet/c-list and https://github.com/joelguittet/c-hashtable
+ * To parse json data from json string use the following: struct <type> * data = cJSON_Parse<type>(<string>);
+ * To get json data from cJSON object use the following: struct <type> * data = cJSON_Get<type>Value(<cjson>);
+ * To get cJSON object from json data use the following: cJSON * cjson = cJSON_Create<type>(<data>);
+ * To print json string from json data use the following: char * string = cJSON_Print<type>(<data>);
+ * To delete json data use the following: cJSON_Delete<type>(<data>);
+ */
+
+#ifndef __TOPLEVEL_H__
+#define __TOPLEVEL_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <regex.h>
+#include <cJSON.h>
+#include <hashtable.h>
+#include <list.h>
+
+#define quicktype_cJSON_Duplicate(j) cJSON_Duplicate(j, true)
+#define cJSON_Integer (1 << 18)
+#define quicktype_cJSON_IsInteger(j) (cJSON_IsNumber(j) && (j)->valuedouble == (int64_t)(j)->valuedouble)
+#ifndef cJSON_Bool
+#define cJSON_Bool (cJSON_True | cJSON_False)
+#endif
+#ifndef cJSON_Map
+#define cJSON_Map (1 << 16)
+#endif
+#ifndef cJSON_Enum
+#define cJSON_Enum (1 << 17)
+#endif
+
+struct DateTime {
+    int64_t value;
+};
+
+struct EnumValues {
+    char * label;
+};
+
+struct FormatException {
+    int64_t count;
+};
+
+struct RegExp {
+    bool active;
+};
+
+enum Status {
+    STATUS_READY = 1,
+    STATUS_DONE,
+};
+
+struct TopLevel {
+    char * code;
+    struct DateTime * date_time;
+    struct EnumValues * enum_values;
+    struct FormatException * format_exception;
+    struct RegExp * reg_exp;
+    enum Status status;
+    char * timestamp;
+};
+
+enum Status cJSON_GetStatusValue(const cJSON * j);
+cJSON * cJSON_CreateStatus(const enum Status x);
+
+struct DateTime * cJSON_ParseDateTime(const char * s);
+struct DateTime * cJSON_GetDateTimeValue(const cJSON * j);
+cJSON * cJSON_CreateDateTime(const struct DateTime * x);
+char * cJSON_PrintDateTime(const struct DateTime * x);
+void cJSON_DeleteDateTime(struct DateTime * x);
+
+struct EnumValues * cJSON_ParseEnumValues(const char * s);
+struct EnumValues * cJSON_GetEnumValuesValue(const cJSON * j);
+cJSON * cJSON_CreateEnumValues(const struct EnumValues * x);
+char * cJSON_PrintEnumValues(const struct EnumValues * x);
+void cJSON_DeleteEnumValues(struct EnumValues * x);
+
+struct FormatException * cJSON_ParseFormatException(const char * s);
+struct FormatException * cJSON_GetFormatExceptionValue(const cJSON * j);
+cJSON * cJSON_CreateFormatException(const struct FormatException * x);
+char * cJSON_PrintFormatException(const struct FormatException * x);
+void cJSON_DeleteFormatException(struct FormatException * x);
+
+struct RegExp * cJSON_ParseRegExp(const char * s);
+struct RegExp * cJSON_GetRegExpValue(const cJSON * j);
+cJSON * cJSON_CreateRegExp(const struct RegExp * x);
+char * cJSON_PrintRegExp(const struct RegExp * x);
+void cJSON_DeleteRegExp(struct RegExp * x);
+
+struct TopLevel * cJSON_ParseTopLevel(const char * s);
+struct TopLevel * cJSON_GetTopLevelValue(const cJSON * j);
+cJSON * cJSON_CreateTopLevel(const struct TopLevel * x);
+char * cJSON_PrintTopLevel(const struct TopLevel * x);
+void cJSON_DeleteTopLevel(struct TopLevel * x);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __TOPLEVEL_H__ */
diff --git a/head/schema-cplusplus/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.hpp b/head/schema-cplusplus/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.hpp
new file mode 100644
index 0000000..97bf1aa
--- /dev/null
+++ b/head/schema-cplusplus/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.hpp
@@ -0,0 +1,368 @@
+//  To parse this JSON data, first install
+//
+//      json.hpp  https://github.com/nlohmann/json
+//
+//  Then include this file, and then do
+//
+//     TopLevel data = nlohmann::json::parse(jsonString);
+
+#pragma once
+
+#include "json.hpp"
+
+#include <optional>
+#include <stdexcept>
+#include <regex>
+
+namespace quicktype {
+    using nlohmann::json;
+
+    class ClassMemberConstraints {
+        private:
+        std::optional<int64_t> min_int_value;
+        std::optional<int64_t> max_int_value;
+        std::optional<double> min_double_value;
+        std::optional<double> max_double_value;
+        std::optional<size_t> min_length;
+        std::optional<size_t> max_length;
+        std::optional<std::string> pattern;
+
+        public:
+        ClassMemberConstraints(
+            std::optional<int64_t> min_int_value,
+            std::optional<int64_t> max_int_value,
+            std::optional<double> min_double_value,
+            std::optional<double> max_double_value,
+            std::optional<size_t> min_length,
+            std::optional<size_t> max_length,
+            std::optional<std::string> pattern
+        ) : min_int_value(min_int_value), max_int_value(max_int_value), min_double_value(min_double_value), max_double_value(max_double_value), min_length(min_length), max_length(max_length), pattern(pattern) {}
+        ClassMemberConstraints() = default;
+        virtual ~ClassMemberConstraints() = default;
+
+        void set_min_int_value(int64_t min_int_value) { this->min_int_value = min_int_value; }
+        auto get_min_int_value() const { return min_int_value; }
+
+        void set_max_int_value(int64_t max_int_value) { this->max_int_value = max_int_value; }
+        auto get_max_int_value() const { return max_int_value; }
+
+        void set_min_double_value(double min_double_value) { this->min_double_value = min_double_value; }
+        auto get_min_double_value() const { return min_double_value; }
+
+        void set_max_double_value(double max_double_value) { this->max_double_value = max_double_value; }
+        auto get_max_double_value() const { return max_double_value; }
+
+        void set_min_length(size_t min_length) { this->min_length = min_length; }
+        auto get_min_length() const { return min_length; }
+
+        void set_max_length(size_t max_length) { this->max_length = max_length; }
+        auto get_max_length() const { return max_length; }
+
+        void set_pattern(const std::string &  pattern) { this->pattern = pattern; }
+        auto get_pattern() const { return pattern; }
+    };
+
+    class ClassMemberConstraintException : public std::runtime_error {
+        public:
+        ClassMemberConstraintException(const std::string &  msg) : std::runtime_error(msg) {}
+    };
+
+    class ValueTooLowException : public ClassMemberConstraintException {
+        public:
+        ValueTooLowException(const std::string &  msg) : ClassMemberConstraintException(msg) {}
+    };
+
+    class ValueTooHighException : public ClassMemberConstraintException {
+        public:
+        ValueTooHighException(const std::string &  msg) : ClassMemberConstraintException(msg) {}
+    };
+
+    class ValueTooShortException : public ClassMemberConstraintException {
+        public:
+        ValueTooShortException(const std::string &  msg) : ClassMemberConstraintException(msg) {}
+    };
+
+    class ValueTooLongException : public ClassMemberConstraintException {
+        public:
+        ValueTooLongException(const std::string &  msg) : ClassMemberConstraintException(msg) {}
+    };
+
+    class InvalidPatternException : public ClassMemberConstraintException {
+        public:
+        InvalidPatternException(const std::string &  msg) : ClassMemberConstraintException(msg) {}
+    };
+
+    inline void CheckConstraint(const std::string &  name, const ClassMemberConstraints & c, int64_t value) {
+        if (c.get_min_int_value() != std::nullopt && value < *c.get_min_int_value()) {
+            throw ValueTooLowException ("Value too low for " + name + " (" + std::to_string(value) + "<" + std::to_string(*c.get_min_int_value()) + ")");
+        }
+
+        if (c.get_max_int_value() != std::nullopt && value > *c.get_max_int_value()) {
+            throw ValueTooHighException ("Value too high for " + name + " (" + std::to_string(value) + ">" + std::to_string(*c.get_max_int_value()) + ")");
+        }
+    }
+
+    inline void CheckConstraint(const std::string &  name, const ClassMemberConstraints & c, const std::optional<int64_t> & value) {
+        if (value) {
+            CheckConstraint(name, c, *value);
+        }
+    }
+
+    inline void CheckConstraint(const std::string &  name, const ClassMemberConstraints & c, double value) {
+        if (c.get_min_double_value() != std::nullopt && value < *c.get_min_double_value()) {
+            throw ValueTooLowException ("Value too low for " + name + " (" + std::to_string(value) + "<" + std::to_string(*c.get_min_double_value()) + ")");
+        }
+
+        if (c.get_max_double_value() != std::nullopt && value > *c.get_max_double_value()) {
+            throw ValueTooHighException ("Value too high for " + name + " (" + std::to_string(value) + ">" + std::to_string(*c.get_max_double_value()) + ")");
+        }
+    }
+
+    inline void CheckConstraint(const std::string &  name, const ClassMemberConstraints & c, const std::optional<double> & value) {
+        if (value) {
+            CheckConstraint(name, c, *value);
+        }
+    }
+
+    inline void CheckConstraint(const std::string &  name, const ClassMemberConstraints & c, const std::string &  value) {
+        if (c.get_min_length() != std::nullopt && value.length() < *c.get_min_length()) {
+            throw ValueTooShortException ("Value too short for " + name + " (" + std::to_string(value.length()) + "<" + std::to_string(*c.get_min_length()) + ")");
+        }
+
+        if (c.get_max_length() != std::nullopt && value.length() > *c.get_max_length()) {
+            throw ValueTooLongException ("Value too long for " + name + " (" + std::to_string(value.length()) + ">" + std::to_string(*c.get_max_length()) + ")");
+        }
+
+        if (c.get_pattern() != std::nullopt) {
+            std::smatch result;
+            std::regex_search(value, result, std::regex( *c.get_pattern() ));
+            if (result.empty()) {
+                throw InvalidPatternException ("Value doesn't match pattern for " + name + " (" + value +" != " + *c.get_pattern() + ")");
+            }
+        }
+    }
+
+    inline void CheckConstraint(const std::string &  name, const ClassMemberConstraints & c, const std::optional<std::string> & value) {
+        if (value) {
+            CheckConstraint(name, c, *value);
+        }
+    }
+
+    #ifndef NLOHMANN_UNTYPED_quicktype_HELPER
+    #define NLOHMANN_UNTYPED_quicktype_HELPER
+    inline json get_untyped(const json & j, const char * property) {
+        if (j.find(property) != j.end()) {
+            return j.at(property).get<json>();
+        }
+        return json();
+    }
+
+    inline json get_untyped(const json & j, std::string property) {
+        return get_untyped(j, property.data());
+    }
+    #endif
+
+    class DateTime {
+        public:
+        DateTime() = default;
+        virtual ~DateTime() = default;
+
+        private:
+        int64_t value;
+
+        public:
+        const int64_t & get_value() const { return value; }
+        int64_t & get_mutable_value() { return value; }
+        void set_value(const int64_t & value) { this->value = value; }
+    };
+
+    class EnumValues {
+        public:
+        EnumValues() = default;
+        virtual ~EnumValues() = default;
+
+        private:
+        std::string label;
+
+        public:
+        const std::string & get_label() const { return label; }
+        std::string & get_mutable_label() { return label; }
+        void set_label(const std::string & value) { this->label = value; }
+    };
+
+    class FormatException {
+        public:
+        FormatException() = default;
+        virtual ~FormatException() = default;
+
+        private:
+        int64_t count;
+
+        public:
+        const int64_t & get_count() const { return count; }
+        int64_t & get_mutable_count() { return count; }
+        void set_count(const int64_t & value) { this->count = value; }
+    };
+
+    class RegExp {
+        public:
+        RegExp() = default;
+        virtual ~RegExp() = default;
+
+        private:
+        bool active;
+
+        public:
+        const bool & get_active() const { return active; }
+        bool & get_mutable_active() { return active; }
+        void set_active(const bool & value) { this->active = value; }
+    };
+
+    enum class Status : int { READY, DONE };
+
+    class TopLevel {
+        public:
+        TopLevel() :
+            code_constraint(std::nullopt, std::nullopt, std::nullopt, std::nullopt, 1, std::nullopt, std::string("^[a-z]+$"))
+        {}
+        virtual ~TopLevel() = default;
+
+        private:
+        std::string code;
+        ClassMemberConstraints code_constraint;
+        DateTime date_time;
+        EnumValues enum_values;
+        FormatException format_exception;
+        RegExp reg_exp;
+        Status status;
+        std::string timestamp;
+
+        public:
+        const std::string & get_code() const { return code; }
+        std::string & get_mutable_code() { return code; }
+        void set_code(const std::string & value) { CheckConstraint("code", code_constraint, value); this->code = value; }
+
+        const DateTime & get_date_time() const { return date_time; }
+        DateTime & get_mutable_date_time() { return date_time; }
+        void set_date_time(const DateTime & value) { this->date_time = value; }
+
+        const EnumValues & get_enum_values() const { return enum_values; }
+        EnumValues & get_mutable_enum_values() { return enum_values; }
+        void set_enum_values(const EnumValues & value) { this->enum_values = value; }
+
+        const FormatException & get_format_exception() const { return format_exception; }
+        FormatException & get_mutable_format_exception() { return format_exception; }
+        void set_format_exception(const FormatException & value) { this->format_exception = value; }
+
+        const RegExp & get_reg_exp() const { return reg_exp; }
+        RegExp & get_mutable_reg_exp() { return reg_exp; }
+        void set_reg_exp(const RegExp & value) { this->reg_exp = value; }
+
+        const Status & get_status() const { return status; }
+        Status & get_mutable_status() { return status; }
+        void set_status(const Status & value) { this->status = value; }
+
+        const std::string & get_timestamp() const { return timestamp; }
+        std::string & get_mutable_timestamp() { return timestamp; }
+        void set_timestamp(const std::string & value) { this->timestamp = value; }
+    };
+}
+
+namespace quicktype {
+    void from_json(const json & j, DateTime & x);
+    void to_json(json & j, const DateTime & x);
+
+    void from_json(const json & j, EnumValues & x);
+    void to_json(json & j, const EnumValues & x);
+
+    void from_json(const json & j, FormatException & x);
+    void to_json(json & j, const FormatException & x);
+
+    void from_json(const json & j, RegExp & x);
+    void to_json(json & j, const RegExp & x);
+
+    void from_json(const json & j, TopLevel & x);
+    void to_json(json & j, const TopLevel & x);
+
+    void from_json(const json & j, Status & x);
+    void to_json(json & j, const Status & x);
+
+    inline void from_json(const json & j, DateTime& x) {
+        if (!j.is_object()) throw std::runtime_error("Expected object");
+        if (j.find("value") != j.end() && !j.at("value").is_number_integer()) throw std::runtime_error("Expected integer");
+        x.set_value(j.at("value").get<int64_t>());
+    }
+
+    inline void to_json(json & j, const DateTime & x) {
+        j = json::object();
+        j["value"] = x.get_value();
+    }
+
+    inline void from_json(const json & j, EnumValues& x) {
+        if (!j.is_object()) throw std::runtime_error("Expected object");
+        x.set_label(j.at("label").get<std::string>());
+    }
+
+    inline void to_json(json & j, const EnumValues & x) {
+        j = json::object();
+        j["label"] = x.get_label();
+    }
+
+    inline void from_json(const json & j, FormatException& x) {
+        if (!j.is_object()) throw std::runtime_error("Expected object");
+        if (j.find("count") != j.end() && !j.at("count").is_number_integer()) throw std::runtime_error("Expected integer");
+        x.set_count(j.at("count").get<int64_t>());
+    }
+
+    inline void to_json(json & j, const FormatException & x) {
+        j = json::object();
+        j["count"] = x.get_count();
+    }
+
+    inline void from_json(const json & j, RegExp& x) {
+        if (!j.is_object()) throw std::runtime_error("Expected object");
+        x.set_active(j.at("active").get<bool>());
+    }
+
+    inline void to_json(json & j, const RegExp & x) {
+        j = json::object();
+        j["active"] = x.get_active();
+    }
+
+    inline void from_json(const json & j, TopLevel& x) {
+        if (!j.is_object()) throw std::runtime_error("Expected object");
+        x.set_code(j.at("code").get<std::string>());
+        x.set_date_time(j.at("dateTime").get<DateTime>());
+        x.set_enum_values(j.at("enumValues").get<EnumValues>());
+        x.set_format_exception(j.at("formatException").get<FormatException>());
+        x.set_reg_exp(j.at("regExp").get<RegExp>());
+        x.set_status(j.at("status").get<Status>());
+        if (j.find("timestamp") != j.end() && !std::regex_match(j.at("timestamp").get<std::string>(), std::regex("^[0-9]{4}-[0-9]{2}-[0-9]{2}T.*$"))) throw std::runtime_error("Expected date-time");
+        x.set_timestamp(j.at("timestamp").get<std::string>());
+    }
+
+    inline void to_json(json & j, const TopLevel & x) {
+        j = json::object();
+        j["code"] = x.get_code();
+        j["dateTime"] = x.get_date_time();
+        j["enumValues"] = x.get_enum_values();
+        j["formatException"] = x.get_format_exception();
+        j["regExp"] = x.get_reg_exp();
+        j["status"] = x.get_status();
+        j["timestamp"] = x.get_timestamp();
+    }
+
+    inline void from_json(const json & j, Status & x) {
+        if (j == "ready") x = Status::READY;
+        else if (j == "done") x = Status::DONE;
+        else { throw std::runtime_error("Cannot deserialize to enumeration \"Status\""); }
+    }
+
+    inline void to_json(json & j, const Status & x) {
+        switch (x) {
+            case Status::READY: j = "ready"; break;
+            case Status::DONE: j = "done"; break;
+            default: throw std::runtime_error("Unexpected value in enumeration \"Status\": " + std::to_string(static_cast<int>(x)));
+        }
+    }
+}
diff --git a/head/schema-crystal/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.cr b/head/schema-crystal/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.cr
new file mode 100644
index 0000000..4836f1b
--- /dev/null
+++ b/head/schema-crystal/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.cr
@@ -0,0 +1,47 @@
+require "json"
+
+class TopLevel
+  include JSON::Serializable
+
+  property code : String
+
+  @[JSON::Field(key: "dateTime")]
+  property date_time : DateTime
+
+  @[JSON::Field(key: "enumValues")]
+  property enum_values : EnumValues
+
+  @[JSON::Field(key: "formatException")]
+  property format_exception : FormatException
+
+  @[JSON::Field(key: "regExp")]
+  property reg_exp : RegExp
+
+  property status : String
+
+  property timestamp : String
+end
+
+class DateTime
+  include JSON::Serializable
+
+  property value : Int64
+end
+
+class EnumValues
+  include JSON::Serializable
+
+  property label : String
+end
+
+class FormatException
+  include JSON::Serializable
+
+  property count : Int64
+end
+
+class RegExp
+  include JSON::Serializable
+
+  property active : Bool
+end
diff --git a/head/schema-csharp/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.cs b/head/schema-csharp/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.cs
new file mode 100644
index 0000000..32f5373
--- /dev/null
+++ b/head/schema-csharp/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.cs
@@ -0,0 +1,176 @@
+// <auto-generated />
+//
+// To parse this JSON data, add NuGet 'Newtonsoft.Json' then do:
+//
+//    using QuickType;
+//
+//    var topLevel = TopLevel.FromJson(jsonString);
+#nullable enable
+#pragma warning disable CS8618
+#pragma warning disable CS8601
+#pragma warning disable CS8602
+#pragma warning disable CS8603
+#pragma warning disable CS8604
+#pragma warning disable CS8625
+#pragma warning disable CS8765
+
+namespace QuickType
+{
+    using System;
+    using System.Collections.Generic;
+
+    using System.Globalization;
+    using Newtonsoft.Json;
+    using Newtonsoft.Json.Converters;
+
+    public partial class TopLevel
+    {
+        [JsonProperty("code", Required = Required.Always)]
+        [JsonConverter(typeof(MinMaxLengthCheckConverter))]
+        public string Code { get; set; }
+
+        [JsonProperty("dateTime", Required = Required.Always)]
+        public DateTime DateTime { get; set; }
+
+        [JsonProperty("enumValues", Required = Required.Always)]
+        public EnumValues EnumValues { get; set; }
+
+        [JsonProperty("formatException", Required = Required.Always)]
+        public FormatException FormatException { get; set; }
+
+        [JsonProperty("regExp", Required = Required.Always)]
+        public RegExp RegExp { get; set; }
+
+        [JsonProperty("status", Required = Required.Always)]
+        public Status Status { get; set; }
+
+        [JsonProperty("timestamp", Required = Required.Always)]
+        public DateTimeOffset Timestamp { get; set; }
+    }
+
+    public partial class DateTime
+    {
+        [JsonProperty("value", Required = Required.Always)]
+        public long Value { get; set; }
+    }
+
+    public partial class EnumValues
+    {
+        [JsonProperty("label", Required = Required.Always)]
+        public string Label { get; set; }
+    }
+
+    public partial class FormatException
+    {
+        [JsonProperty("count", Required = Required.Always)]
+        public long Count { get; set; }
+    }
+
+    public partial class RegExp
+    {
+        [JsonProperty("active", Required = Required.Always)]
+        public bool Active { get; set; }
+    }
+
+    public enum Status { Ready, Done };
+
+    public partial class TopLevel
+    {
+        public static TopLevel FromJson(string json) => JsonConvert.DeserializeObject<TopLevel>(json, QuickType.Converter.Settings);
+    }
+
+    public static partial class Serialize
+    {
+        public static string ToJson(this TopLevel self) => JsonConvert.SerializeObject(self, QuickType.Converter.Settings);
+    }
+
+    internal static partial class Converter
+    {
+        public static readonly JsonSerializerSettings Settings = new JsonSerializerSettings
+        {
+            MetadataPropertyHandling = MetadataPropertyHandling.Ignore,
+            DateParseHandling = DateParseHandling.None,
+            Converters =
+            {
+                StatusConverter.Singleton,
+                new IsoDateTimeConverter { DateTimeStyles = DateTimeStyles.AssumeUniversal }
+            },
+        };
+    }
+
+    internal class MinMaxLengthCheckConverter : JsonConverter
+    {
+        public override bool CanConvert(Type t) => t == typeof(string);
+
+        public override object ReadJson(JsonReader reader, Type t, object existingValue, JsonSerializer serializer)
+        {
+            var value = serializer.Deserialize<string>(reader);
+            if (value.Length >= 1)
+            {
+                return value;
+            }
+            throw new Exception("Cannot unmarshal type string");
+        }
+
+        public override void WriteJson(JsonWriter writer, object untypedValue, JsonSerializer serializer)
+        {
+            var value = (string)untypedValue;
+            if (value.Length >= 1)
+            {
+                serializer.Serialize(writer, value);
+                return;
+            }
+            throw new Exception("Cannot marshal type string");
+        }
+
+        public static readonly MinMaxLengthCheckConverter Singleton = new MinMaxLengthCheckConverter();
+    }
+
+    internal class StatusConverter : JsonConverter
+    {
+        public override bool CanConvert(Type t) => t == typeof(Status) || t == typeof(Status?);
+
+        public override object ReadJson(JsonReader reader, Type t, object existingValue, JsonSerializer serializer)
+        {
+            if (reader.TokenType == JsonToken.Null) return null;
+            var value = serializer.Deserialize<string>(reader);
+            switch (value)
+            {
+                case "ready":
+                    return Status.Ready;
+                case "done":
+                    return Status.Done;
+            }
+            throw new Exception("Cannot unmarshal type Status");
+        }
+
+        public override void WriteJson(JsonWriter writer, object untypedValue, JsonSerializer serializer)
+        {
+            if (untypedValue == null)
+            {
+                serializer.Serialize(writer, null);
+                return;
+            }
+            var value = (Status)untypedValue;
+            switch (value)
+            {
+                case Status.Ready:
+                    serializer.Serialize(writer, "ready");
+                    return;
+                case Status.Done:
+                    serializer.Serialize(writer, "done");
+                    return;
+            }
+            throw new Exception("Cannot marshal type Status");
+        }
+
+        public static readonly StatusConverter Singleton = new StatusConverter();
+    }
+}
+#pragma warning restore CS8618
+#pragma warning restore CS8601
+#pragma warning restore CS8602
+#pragma warning restore CS8603
+#pragma warning restore CS8604
+#pragma warning restore CS8625
+#pragma warning restore CS8765
diff --git a/head/schema-csharp-SystemTextJson/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.cs b/head/schema-csharp-SystemTextJson/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.cs
new file mode 100644
index 0000000..3d17650
--- /dev/null
+++ b/head/schema-csharp-SystemTextJson/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.cs
@@ -0,0 +1,283 @@
+// <auto-generated />
+//
+// To parse this JSON data, add NuGet 'System.Text.Json' then do:
+//
+//    using QuickType;
+//
+//    var topLevel = TopLevel.FromJson(jsonString);
+#nullable enable
+#pragma warning disable CS8618
+#pragma warning disable CS8601
+#pragma warning disable CS8602
+#pragma warning disable CS8603
+
+namespace QuickType
+{
+    using System;
+    using System.Collections.Generic;
+
+    using System.Text.Json;
+    using System.Text.Json.Serialization;
+    using System.Globalization;
+
+    public partial class TopLevel
+    {
+        [JsonRequired]
+        [JsonPropertyName("code")]
+        [JsonConverter(typeof(MinMaxLengthCheckConverter))]
+        public string Code { get; set; }
+
+        [JsonRequired]
+        [JsonPropertyName("dateTime")]
+        public DateTime DateTime { get; set; }
+
+        [JsonRequired]
+        [JsonPropertyName("enumValues")]
+        public EnumValues EnumValues { get; set; }
+
+        [JsonRequired]
+        [JsonPropertyName("formatException")]
+        public FormatException FormatException { get; set; }
+
+        [JsonRequired]
+        [JsonPropertyName("regExp")]
+        public RegExp RegExp { get; set; }
+
+        [JsonRequired]
+        [JsonPropertyName("status")]
+        public Status Status { get; set; }
+
+        [JsonRequired]
+        [JsonPropertyName("timestamp")]
+        public DateTimeOffset Timestamp { get; set; }
+    }
+
+    public partial class DateTime
+    {
+        [JsonRequired]
+        [JsonPropertyName("value")]
+        public long Value { get; set; }
+    }
+
+    public partial class EnumValues
+    {
+        [JsonRequired]
+        [JsonPropertyName("label")]
+        public string Label { get; set; }
+    }
+
+    public partial class FormatException
+    {
+        [JsonRequired]
+        [JsonPropertyName("count")]
+        public long Count { get; set; }
+    }
+
+    public partial class RegExp
+    {
+        [JsonRequired]
+        [JsonPropertyName("active")]
+        public bool Active { get; set; }
+    }
+
+    public enum Status { Ready, Done };
+
+    public partial class TopLevel
+    {
+        public static TopLevel FromJson(string json) => global::System.Text.Json.JsonSerializer.Deserialize<TopLevel>(json, QuickType.Converter.Settings);
+    }
+
+    public static partial class Serialize
+    {
+        public static string ToJson(this TopLevel self) => JsonSerializer.Serialize(self, QuickType.Converter.Settings);
+    }
+
+    internal static partial class Converter
+    {
+        public static readonly JsonSerializerOptions Settings = new(JsonSerializerDefaults.General)
+        {
+            Converters =
+            {
+                StatusConverter.Singleton,
+                new DateOnlyConverter(),
+                new TimeOnlyConverter(),
+                IsoDateTimeOffsetConverter.Singleton
+            },
+        };
+    }
+
+    internal class MinMaxLengthCheckConverter : JsonConverter<string>
+    {
+        public override bool CanConvert(Type t) => t == typeof(string);
+
+        public override string Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            var value = reader.GetString();
+            if (value.Length >= 1)
+            {
+                return value;
+            }
+            throw new JsonException("Cannot unmarshal type string");
+        }
+
+        public override void Write(Utf8JsonWriter writer, string value, JsonSerializerOptions options)
+        {
+            if (value.Length >= 1)
+            {
+                JsonSerializer.Serialize(writer, value, options);
+                return;
+            }
+            throw new NotSupportedException("Cannot marshal type string");
+        }
+
+        public static readonly MinMaxLengthCheckConverter Singleton = new MinMaxLengthCheckConverter();
+    }
+
+    internal class StatusConverter : JsonConverter<Status>
+    {
+        public override bool CanConvert(Type t) => t == typeof(Status);
+
+        public override Status Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            var value = reader.GetString();
+            switch (value)
+            {
+                case "ready":
+                    return Status.Ready;
+                case "done":
+                    return Status.Done;
+            }
+            throw new JsonException("Cannot unmarshal type Status");
+        }
+
+        public override void Write(Utf8JsonWriter writer, Status value, JsonSerializerOptions options)
+        {
+            switch (value)
+            {
+                case Status.Ready:
+                    JsonSerializer.Serialize(writer, "ready", options);
+                    return;
+                case Status.Done:
+                    JsonSerializer.Serialize(writer, "done", options);
+                    return;
+            }
+            throw new NotSupportedException("Cannot marshal type Status");
+        }
+
+        public static readonly StatusConverter Singleton = new StatusConverter();
+    }
+    
+    public class DateOnlyConverter : JsonConverter<DateOnly>
+    {
+        private readonly string serializationFormat;
+        public DateOnlyConverter() : this(null) { }
+
+        public DateOnlyConverter(string? serializationFormat)
+        {
+                this.serializationFormat = serializationFormat ?? "yyyy-MM-dd";
+        }
+
+        public override DateOnly Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+                var value = reader.GetString();
+                return DateOnly.Parse(value!);
+        }
+
+        public override void Write(Utf8JsonWriter writer, DateOnly value, JsonSerializerOptions options)
+                => writer.WriteStringValue(value.ToString(serializationFormat));
+    }
+
+    public class TimeOnlyConverter : JsonConverter<TimeOnly>
+    {
+        private readonly string serializationFormat;
+
+        public TimeOnlyConverter() : this(null) { }
+
+        public TimeOnlyConverter(string? serializationFormat)
+        {
+                this.serializationFormat = serializationFormat ?? "HH:mm:ss.fff";
+        }
+
+        public override TimeOnly Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+                var value = reader.GetString();
+                return TimeOnly.Parse(value!);
+        }
+
+        public override void Write(Utf8JsonWriter writer, TimeOnly value, JsonSerializerOptions options)
+                => writer.WriteStringValue(value.ToString(serializationFormat));
+    }
+
+    internal class IsoDateTimeOffsetConverter : JsonConverter<DateTimeOffset>
+    {
+        public override bool CanConvert(Type t) => t == typeof(DateTimeOffset);
+
+        private const string DefaultDateTimeFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ss.FFFFFFFK";
+
+        private DateTimeStyles _dateTimeStyles = DateTimeStyles.RoundtripKind;
+        private string? _dateTimeFormat;
+        private CultureInfo? _culture;
+
+        public DateTimeStyles DateTimeStyles
+        {
+                get => _dateTimeStyles;
+                set => _dateTimeStyles = value;
+        }
+
+        public string? DateTimeFormat
+        {
+                get => _dateTimeFormat ?? string.Empty;
+                set => _dateTimeFormat = (string.IsNullOrEmpty(value)) ? null : value;
+        }
+
+        public CultureInfo Culture
+        {
+                get => _culture ?? CultureInfo.CurrentCulture;
+                set => _culture = value;
+        }
+
+        public override void Write(Utf8JsonWriter writer, DateTimeOffset value, JsonSerializerOptions options)
+        {
+                string text;
+
+
+                if ((_dateTimeStyles & DateTimeStyles.AdjustToUniversal) == DateTimeStyles.AdjustToUniversal
+                        || (_dateTimeStyles & DateTimeStyles.AssumeUniversal) == DateTimeStyles.AssumeUniversal)
+                {
+                        value = value.ToUniversalTime();
+                }
+
+                text = value.ToString(_dateTimeFormat ?? DefaultDateTimeFormat, Culture);
+
+                writer.WriteStringValue(text);
+        }
+
+        public override DateTimeOffset Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+                string? dateText = reader.GetString();
+
+                if (string.IsNullOrEmpty(dateText) == false)
+                {
+                        if (!string.IsNullOrEmpty(_dateTimeFormat))
+                        {
+                                return DateTimeOffset.ParseExact(dateText, _dateTimeFormat, Culture, _dateTimeStyles);
+                        }
+                        else
+                        {
+                                return DateTimeOffset.Parse(dateText, Culture, _dateTimeStyles);
+                        }
+                }
+                else
+                {
+                        return default(DateTimeOffset);
+                }
+        }
+
+
+        public static readonly IsoDateTimeOffsetConverter Singleton = new IsoDateTimeOffsetConverter();
+    }
+}
+#pragma warning restore CS8618
+#pragma warning restore CS8601
+#pragma warning restore CS8602
+#pragma warning restore CS8603
diff --git a/head/schema-csharp-records/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.cs b/head/schema-csharp-records/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.cs
new file mode 100644
index 0000000..c282d2e
--- /dev/null
+++ b/head/schema-csharp-records/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.cs
@@ -0,0 +1,176 @@
+// <auto-generated />
+//
+// To parse this JSON data, add NuGet 'Newtonsoft.Json' then do:
+//
+//    using QuickType;
+//
+//    var topLevel = TopLevel.FromJson(jsonString);
+#nullable enable
+#pragma warning disable CS8618
+#pragma warning disable CS8601
+#pragma warning disable CS8602
+#pragma warning disable CS8603
+#pragma warning disable CS8604
+#pragma warning disable CS8625
+#pragma warning disable CS8765
+
+namespace QuickType
+{
+    using System;
+    using System.Collections.Generic;
+
+    using System.Globalization;
+    using Newtonsoft.Json;
+    using Newtonsoft.Json.Converters;
+
+    public partial record TopLevel
+    {
+        [JsonProperty("code", Required = Required.Always)]
+        [JsonConverter(typeof(MinMaxLengthCheckConverter))]
+        public string Code { get; set; }
+
+        [JsonProperty("dateTime", Required = Required.Always)]
+        public DateTime DateTime { get; set; }
+
+        [JsonProperty("enumValues", Required = Required.Always)]
+        public EnumValues EnumValues { get; set; }
+
+        [JsonProperty("formatException", Required = Required.Always)]
+        public FormatException FormatException { get; set; }
+
+        [JsonProperty("regExp", Required = Required.Always)]
+        public RegExp RegExp { get; set; }
+
+        [JsonProperty("status", Required = Required.Always)]
+        public Status Status { get; set; }
+
+        [JsonProperty("timestamp", Required = Required.Always)]
+        public DateTimeOffset Timestamp { get; set; }
+    }
+
+    public partial record DateTime
+    {
+        [JsonProperty("value", Required = Required.Always)]
+        public long Value { get; set; }
+    }
+
+    public partial record EnumValues
+    {
+        [JsonProperty("label", Required = Required.Always)]
+        public string Label { get; set; }
+    }
+
+    public partial record FormatException
+    {
+        [JsonProperty("count", Required = Required.Always)]
+        public long Count { get; set; }
+    }
+
+    public partial record RegExp
+    {
+        [JsonProperty("active", Required = Required.Always)]
+        public bool Active { get; set; }
+    }
+
+    public enum Status { Ready, Done };
+
+    public partial record TopLevel
+    {
+        public static TopLevel FromJson(string json) => JsonConvert.DeserializeObject<TopLevel>(json, QuickType.Converter.Settings);
+    }
+
+    public static partial class Serialize
+    {
+        public static string ToJson(this TopLevel self) => JsonConvert.SerializeObject(self, QuickType.Converter.Settings);
+    }
+
+    internal static partial class Converter
+    {
+        public static readonly JsonSerializerSettings Settings = new JsonSerializerSettings
+        {
+            MetadataPropertyHandling = MetadataPropertyHandling.Ignore,
+            DateParseHandling = DateParseHandling.None,
+            Converters =
+            {
+                StatusConverter.Singleton,
+                new IsoDateTimeConverter { DateTimeStyles = DateTimeStyles.AssumeUniversal }
+            },
+        };
+    }
+
+    internal class MinMaxLengthCheckConverter : JsonConverter
+    {
+        public override bool CanConvert(Type t) => t == typeof(string);
+
+        public override object ReadJson(JsonReader reader, Type t, object existingValue, JsonSerializer serializer)
+        {
+            var value = serializer.Deserialize<string>(reader);
+            if (value.Length >= 1)
+            {
+                return value;
+            }
+            throw new Exception("Cannot unmarshal type string");
+        }
+
+        public override void WriteJson(JsonWriter writer, object untypedValue, JsonSerializer serializer)
+        {
+            var value = (string)untypedValue;
+            if (value.Length >= 1)
+            {
+                serializer.Serialize(writer, value);
+                return;
+            }
+            throw new Exception("Cannot marshal type string");
+        }
+
+        public static readonly MinMaxLengthCheckConverter Singleton = new MinMaxLengthCheckConverter();
+    }
+
+    internal class StatusConverter : JsonConverter
+    {
+        public override bool CanConvert(Type t) => t == typeof(Status) || t == typeof(Status?);
+
+        public override object ReadJson(JsonReader reader, Type t, object existingValue, JsonSerializer serializer)
+        {
+            if (reader.TokenType == JsonToken.Null) return null;
+            var value = serializer.Deserialize<string>(reader);
+            switch (value)
+            {
+                case "ready":
+                    return Status.Ready;
+                case "done":
+                    return Status.Done;
+            }
+            throw new Exception("Cannot unmarshal type Status");
+        }
+
+        public override void WriteJson(JsonWriter writer, object untypedValue, JsonSerializer serializer)
+        {
+            if (untypedValue == null)
+            {
+                serializer.Serialize(writer, null);
+                return;
+            }
+            var value = (Status)untypedValue;
+            switch (value)
+            {
+                case Status.Ready:
+                    serializer.Serialize(writer, "ready");
+                    return;
+                case Status.Done:
+                    serializer.Serialize(writer, "done");
+                    return;
+            }
+            throw new Exception("Cannot marshal type Status");
+        }
+
+        public static readonly StatusConverter Singleton = new StatusConverter();
+    }
+}
+#pragma warning restore CS8618
+#pragma warning restore CS8601
+#pragma warning restore CS8602
+#pragma warning restore CS8603
+#pragma warning restore CS8604
+#pragma warning restore CS8625
+#pragma warning restore CS8765
diff --git a/head/schema-dart/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.dart b/head/schema-dart/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.dart
new file mode 100644
index 0000000..14fdbde
--- /dev/null
+++ b/head/schema-dart/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.dart
@@ -0,0 +1,135 @@
+// To parse this JSON data, do
+//
+//     final topLevel = topLevelFromJson(jsonString);
+
+import 'dart:convert';
+
+TopLevel topLevelFromJson(String str) => TopLevel.fromJson(json.decode(str));
+
+String topLevelToJson(TopLevel data) => json.encode(data.toJson());
+
+class TopLevel {
+    final String code;
+    final DateTimeClass dateTime;
+    final EnumValuesClass enumValues;
+    final FormatExceptionClass formatException;
+    final RegExpClass regExp;
+    final Status status;
+    final DateTime timestamp;
+
+    TopLevel({
+        required this.code,
+        required this.dateTime,
+        required this.enumValues,
+        required this.formatException,
+        required this.regExp,
+        required this.status,
+        required this.timestamp,
+    });
+
+    factory TopLevel.fromJson(Map<String, dynamic> json) => TopLevel(
+        code: ((x) => RegExp("^[a-z]+\u0024").hasMatch(x) ? x : throw FormatException("Expected matching string"))(((x) => x.length >= 1 && true ? x : throw FormatException("Expected bounded string"))(json["code"])),
+        dateTime: DateTimeClass.fromJson(json["dateTime"]),
+        enumValues: EnumValuesClass.fromJson(json["enumValues"]),
+        formatException: FormatExceptionClass.fromJson(json["formatException"]),
+        regExp: RegExpClass.fromJson(json["regExp"]),
+        status: statusValues.map[json["status"]]!,
+        timestamp: DateTime.parse(json["timestamp"]),
+    );
+
+    Map<String, dynamic> toJson() => {
+        "code": code,
+        "dateTime": dateTime.toJson(),
+        "enumValues": enumValues.toJson(),
+        "formatException": formatException.toJson(),
+        "regExp": regExp.toJson(),
+        "status": statusValues.reverse[status],
+        "timestamp": timestamp.toIso8601String(),
+    };
+}
+
+class DateTimeClass {
+    final int value;
+
+    DateTimeClass({
+        required this.value,
+    });
+
+    factory DateTimeClass.fromJson(Map<String, dynamic> json) => DateTimeClass(
+        value: json["value"],
+    );
+
+    Map<String, dynamic> toJson() => {
+        "value": value,
+    };
+}
+
+class EnumValuesClass {
+    final String label;
+
+    EnumValuesClass({
+        required this.label,
+    });
+
+    factory EnumValuesClass.fromJson(Map<String, dynamic> json) => EnumValuesClass(
+        label: json["label"],
+    );
+
+    Map<String, dynamic> toJson() => {
+        "label": label,
+    };
+}
+
+class FormatExceptionClass {
+    final int count;
+
+    FormatExceptionClass({
+        required this.count,
+    });
+
+    factory FormatExceptionClass.fromJson(Map<String, dynamic> json) => FormatExceptionClass(
+        count: json["count"],
+    );
+
+    Map<String, dynamic> toJson() => {
+        "count": count,
+    };
+}
+
+class RegExpClass {
+    final bool active;
+
+    RegExpClass({
+        required this.active,
+    });
+
+    factory RegExpClass.fromJson(Map<String, dynamic> json) => RegExpClass(
+        active: json["active"],
+    );
+
+    Map<String, dynamic> toJson() => {
+        "active": active,
+    };
+}
+
+enum Status {
+    READY,
+    DONE
+}
+
+final statusValues = EnumValues({
+    "ready": Status.READY,
+    "done": Status.DONE
+});
+
+class EnumValues<T> {
+    Map<String, T> map;
+    late Map<T, String> reverseMap;
+
+    EnumValues(this.map);
+
+    Map<T, String> get reverse {
+            reverseMap = map.map((k, v) => MapEntry(v, k));
+            return reverseMap;
+    }
+}
diff --git a/base/schema-dart/test/inputs/schema/vega-lite.schema/default/TopLevel.dart b/head/schema-dart/test/inputs/schema/vega-lite.schema/default/TopLevel.dart
index 16b29ad..ab4f2be 100644
--- a/base/schema-dart/test/inputs/schema/vega-lite.schema/default/TopLevel.dart
+++ b/head/schema-dart/test/inputs/schema/vega-lite.schema/default/TopLevel.dart
@@ -4840,7 +4840,7 @@ class Predicate {
 ///If both month and quarter are provided, month has higher precedence.
 ///`day` cannot be combined with other date.
 ///We accept string for month and day names.
-class DateTime {
+class DateTimeClass {
     
     ///Integer value representing the date from 1-31.
     final double? date;
@@ -4879,7 +4879,7 @@ class DateTime {
     ///Integer value representing the year.
     final double? year;
 
-    DateTime({
+    DateTimeClass({
         this.date,
         this.day,
         this.hours,
@@ -4892,7 +4892,7 @@ class DateTime {
         this.year,
     });
 
-    factory DateTime.fromJson(Map<String, dynamic> json) => DateTime(
+    factory DateTimeClass.fromJson(Map<String, dynamic> json) => DateTimeClass(
         date: json["date"]?.toDouble() == null ? null : ((x) => x >= 1 && x <= 31 ? x : throw FormatException("Expected bounded number"))(json["date"]?.toDouble()),
         day: json["day"],
         hours: json["hours"]?.toDouble() == null ? null : ((x) => x >= 0 && x <= 23 ? x : throw FormatException("Expected bounded number"))(json["hours"]?.toDouble()),
diff --git a/head/schema-elixir/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.ex b/head/schema-elixir/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.ex
new file mode 100644
index 0000000..dc349c2
--- /dev/null
+++ b/head/schema-elixir/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.ex
@@ -0,0 +1,273 @@
+# This file was autogenerated using quicktype https://github.com/quicktype/quicktype
+#
+# Add Jason to your mix.exs
+#
+# Decode a JSON string: TopLevel.from_json(data)
+# Encode into a JSON string: TopLevel.to_json(struct)
+
+defmodule DateTimeClass do
+  @enforce_keys [:value]
+  defstruct [:value]
+
+  @type t :: %__MODULE__{
+          value: integer()
+        }
+
+  def decode_value(value) when is_integer(value), do: value
+  def decode_value(_), do: {:error, "Unexpected type when decoding DateTimeClass.value"}
+
+  def encode_value(value) when is_integer(value), do: value
+  def encode_value(_), do: {:error, "Unexpected type when encoding DateTimeClass.value"}
+
+  def from_map(m) do
+    %DateTimeClass{
+      value: decode_value(m["value"]),
+    }
+  end
+
+  def from_json(json) do
+    json
+          |> Jason.decode!()
+          |> from_map()
+  end
+
+  def to_map(struct) do
+    %{
+      "value" => struct.value,
+    }
+  end
+
+  def to_json(struct) do
+    struct
+          |> to_map()
+          |> Jason.encode!()
+  end
+end
+
+defmodule EnumValues do
+  @enforce_keys [:label]
+  defstruct [:label]
+
+  @type t :: %__MODULE__{
+          label: String.t()
+        }
+
+  def decode_label(value) when is_binary(value), do: value
+  def decode_label(_), do: {:error, "Unexpected type when decoding EnumValues.label"}
+
+  def encode_label(value) when is_binary(value), do: value
+  def encode_label(_), do: {:error, "Unexpected type when encoding EnumValues.label"}
+
+  def from_map(m) do
+    %EnumValues{
+      label: decode_label(m["label"]),
+    }
+  end
+
+  def from_json(json) do
+    json
+          |> Jason.decode!()
+          |> from_map()
+  end
+
+  def to_map(struct) do
+    %{
+      "label" => struct.label,
+    }
+  end
+
+  def to_json(struct) do
+    struct
+          |> to_map()
+          |> Jason.encode!()
+  end
+end
+
+defmodule FormatException do
+  @enforce_keys [:count]
+  defstruct [:count]
+
+  @type t :: %__MODULE__{
+          count: integer()
+        }
+
+  def decode_count(value) when is_integer(value), do: value
+  def decode_count(_), do: {:error, "Unexpected type when decoding FormatException.count"}
+
+  def encode_count(value) when is_integer(value), do: value
+  def encode_count(_), do: {:error, "Unexpected type when encoding FormatException.count"}
+
+  def from_map(m) do
+    %FormatException{
+      count: decode_count(m["count"]),
+    }
+  end
+
+  def from_json(json) do
+    json
+          |> Jason.decode!()
+          |> from_map()
+  end
+
+  def to_map(struct) do
+    %{
+      "count" => struct.count,
+    }
+  end
+
+  def to_json(struct) do
+    struct
+          |> to_map()
+          |> Jason.encode!()
+  end
+end
+
+defmodule RegExp do
+  @enforce_keys [:active]
+  defstruct [:active]
+
+  @type t :: %__MODULE__{
+          active: boolean()
+        }
+
+  def decode_active(value) when is_boolean(value), do: value
+  def decode_active(_), do: {:error, "Unexpected type when decoding RegExp.active"}
+
+  def encode_active(value) when is_boolean(value), do: value
+  def encode_active(_), do: {:error, "Unexpected type when encoding RegExp.active"}
+
+  def from_map(m) do
+    %RegExp{
+      active: decode_active(m["active"]),
+    }
+  end
+
+  def from_json(json) do
+    json
+          |> Jason.decode!()
+          |> from_map()
+  end
+
+  def to_map(struct) do
+    %{
+      "active" => struct.active,
+    }
+  end
+
+  def to_json(struct) do
+    struct
+          |> to_map()
+          |> Jason.encode!()
+  end
+end
+
+defmodule Status do
+  @valid_enum_members [
+    :ready,
+    :done,
+  ]
+
+  def valid_atom?(value), do: value in @valid_enum_members
+
+  def valid_atom_string?(value) do
+    try do
+        atom = String.to_existing_atom(value)
+        atom in @valid_enum_members
+    rescue
+        ArgumentError -> false
+    end
+  end
+
+  def encode(value) do
+    if valid_atom?(value) do
+        Atom.to_string(value)
+    else
+        {:error, "Unexpected value when encoding atom: #{inspect(value)}"}
+    end
+  end
+
+  def decode(value) do
+    if valid_atom_string?(value) do
+        String.to_existing_atom(value)
+    else
+        {:error, "Unexpected value when decoding atom: #{inspect(value)}"}
+    end
+  end
+
+  def from_json(json) do
+    json
+    |> Jason.decode!()
+    |> decode()
+  end
+
+  def to_json(data) do
+    data
+    |> encode()
+    |> Jason.encode!()
+  end
+end
+
+defmodule TopLevel do
+  @enforce_keys [:code, :date_time, :enum_values, :format_exception, :reg_exp, :status, :timestamp]
+  defstruct [:code, :date_time, :enum_values, :format_exception, :reg_exp, :status, :timestamp]
+
+  @type t :: %__MODULE__{
+          code: String.t(),
+          date_time: DateTimeClass.t(),
+          enum_values: EnumValues.t(),
+          format_exception: FormatException.t(),
+          reg_exp: RegExp.t(),
+          status: Status.t(),
+          timestamp: String.t()
+        }
+
+  def decode_code(value) when is_binary(value) do
+    if String.length(value) >= 1 and Regex.match?(Regex.compile!("^[a-z]+$"), value), do: value, else: raise(ArgumentError)
+  end
+  def decode_code(_), do: {:error, "Unexpected type when decoding TopLevel.code"}
+
+  def encode_code(value) when is_binary(value), do: value
+  def encode_code(_), do: {:error, "Unexpected type when encoding TopLevel.code"}
+
+  def decode_timestamp(value) when is_binary(value), do: value
+  def decode_timestamp(_), do: {:error, "Unexpected type when decoding TopLevel.timestamp"}
+
+  def encode_timestamp(value) when is_binary(value), do: value
+  def encode_timestamp(_), do: {:error, "Unexpected type when encoding TopLevel.timestamp"}
+
+  def from_map(m) do
+    %TopLevel{
+      code: decode_code(m["code"]),
+      date_time: DateTimeClass.from_map(m["dateTime"]),
+      enum_values: EnumValues.from_map(m["enumValues"]),
+      format_exception: FormatException.from_map(m["formatException"]),
+      reg_exp: RegExp.from_map(m["regExp"]),
+      status: Status.decode(m["status"]),
+      timestamp: decode_timestamp(m["timestamp"]),
+    }
+  end
+
+  def from_json(json) do
+    json
+          |> Jason.decode!()
+          |> from_map()
+  end
+
+  def to_map(struct) do
+    %{
+      "code" => struct.code,
+      "dateTime" => DateTimeClass.to_map(struct.date_time),
+      "enumValues" => EnumValues.to_map(struct.enum_values),
+      "formatException" => FormatException.to_map(struct.format_exception),
+      "regExp" => RegExp.to_map(struct.reg_exp),
+      "status" => Status.encode(struct.status),
+      "timestamp" => struct.timestamp,
+    }
+  end
+
+  def to_json(struct) do
+    struct
+          |> to_map()
+          |> Jason.encode!()
+  end
+end
diff --git a/head/schema-elm/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.elm b/head/schema-elm/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.elm
new file mode 100644
index 0000000..c7d531f
--- /dev/null
+++ b/head/schema-elm/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.elm
@@ -0,0 +1,159 @@
+-- To decode the JSON data, add this file to your project, run
+--
+--     elm install NoRedInk/elm-json-decode-pipeline
+--
+-- add these imports
+--
+--     import Json.Decode exposing (decodeString)
+--     import QuickType exposing (quickType)
+--
+-- and you're off to the races with
+--
+--     decodeString quickType myJsonString
+
+module QuickType exposing
+    ( QuickType
+    , quickTypeToString
+    , quickType
+    , DateTime
+    , EnumValues
+    , FormatException
+    , RegExp
+    , Status(..)
+    )
+
+import Json.Decode as Jdec
+import Json.Decode.Pipeline as Jpipe
+import Json.Encode as Jenc
+import Dict exposing (Dict)
+
+type alias QuickType =
+    { code : String
+    , dateTime : DateTime
+    , enumValues : EnumValues
+    , formatException : FormatException
+    , regExp : RegExp
+    , status : Status
+    , timestamp : String
+    }
+
+type alias DateTime =
+    { value : Int
+    }
+
+type alias EnumValues =
+    { label : String
+    }
+
+type alias FormatException =
+    { count : Int
+    }
+
+type alias RegExp =
+    { active : Bool
+    }
+
+type Status
+    = Ready
+    | Done
+
+-- decoders and encoders
+optionalField key decoder fallback =
+    Jdec.dict Jdec.value
+        |> Jdec.andThen (\m ->
+            case Dict.get key m of
+                Nothing -> Jdec.succeed fallback
+                Just x -> Jdec.decodeValue decoder x |> Result.map Jdec.succeed |> Result.withDefault (Jdec.fail ("Invalid " ++ key)))
+
+quickTypeToString : QuickType -> String
+quickTypeToString r = Jenc.encode 0 (encodeQuickType r)
+
+quickType : Jdec.Decoder QuickType
+quickType =
+    Jdec.succeed QuickType
+        |> Jpipe.required "code" (Jdec.andThen (\x -> if String.length x >= 1 && True then Jdec.succeed x else Jdec.fail "String length out of range") Jdec.string)
+        |> Jpipe.required "dateTime" dateTime
+        |> Jpipe.required "enumValues" enumValues
+        |> Jpipe.required "formatException" formatException
+        |> Jpipe.required "regExp" regExp
+        |> Jpipe.required "status" status
+        |> Jpipe.required "timestamp" Jdec.string
+
+encodeQuickType : QuickType -> Jenc.Value
+encodeQuickType x =
+    Jenc.object
+        [ ("code", Jenc.string x.code)
+        , ("dateTime", encodeDateTime x.dateTime)
+        , ("enumValues", encodeEnumValues x.enumValues)
+        , ("formatException", encodeFormatException x.formatException)
+        , ("regExp", encodeRegExp x.regExp)
+        , ("status", encodeStatus x.status)
+        , ("timestamp", Jenc.string x.timestamp)
+        ]
+
+dateTime : Jdec.Decoder DateTime
+dateTime =
+    Jdec.succeed DateTime
+        |> Jpipe.required "value" Jdec.int
+
+encodeDateTime : DateTime -> Jenc.Value
+encodeDateTime x =
+    Jenc.object
+        [ ("value", Jenc.int x.value)
+        ]
+
+enumValues : Jdec.Decoder EnumValues
+enumValues =
+    Jdec.succeed EnumValues
+        |> Jpipe.required "label" Jdec.string
+
+encodeEnumValues : EnumValues -> Jenc.Value
+encodeEnumValues x =
+    Jenc.object
+        [ ("label", Jenc.string x.label)
+        ]
+
+formatException : Jdec.Decoder FormatException
+formatException =
+    Jdec.succeed FormatException
+        |> Jpipe.required "count" Jdec.int
+
+encodeFormatException : FormatException -> Jenc.Value
+encodeFormatException x =
+    Jenc.object
+        [ ("count", Jenc.int x.count)
+        ]
+
+regExp : Jdec.Decoder RegExp
+regExp =
+    Jdec.succeed RegExp
+        |> Jpipe.required "active" Jdec.bool
+
+encodeRegExp : RegExp -> Jenc.Value
+encodeRegExp x =
+    Jenc.object
+        [ ("active", Jenc.bool x.active)
+        ]
+
+status : Jdec.Decoder Status
+status =
+    Jdec.string
+        |> Jdec.andThen (\str ->
+            case str of
+                "ready" -> Jdec.succeed Ready
+                "done" -> Jdec.succeed Done
+                somethingElse -> Jdec.fail <| "Invalid Status: " ++ somethingElse
+        )
+
+encodeStatus : Status -> Jenc.Value
+encodeStatus x = case x of
+    Ready -> Jenc.string "ready"
+    Done -> Jenc.string "done"
+
+--- encoder helpers
+
+makeNullableEncoder : (a -> Jenc.Value) -> Maybe a -> Jenc.Value
+makeNullableEncoder f m =
+    case m of
+    Just x -> f x
+    Nothing -> Jenc.null
diff --git a/head/schema-flow/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.js b/head/schema-flow/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.js
new file mode 100644
index 0000000..635caac
--- /dev/null
+++ b/head/schema-flow/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.js
@@ -0,0 +1,261 @@
+// @flow
+
+// To parse this data:
+//
+//   const Convert = require("./TopLevel");
+//
+//   const topLevel = Convert.toTopLevel(json);
+//
+// These functions will throw an error if the JSON doesn't
+// match the expected interface, even if the JSON is valid.
+
+export type TopLevel = {
+    code:            string;
+    dateTime:        DateTime;
+    enumValues:      EnumValues;
+    formatException: FormatException;
+    regExp:          RegExp;
+    status:          Status;
+    timestamp:       Date;
+};
+
+export type DateTime = {
+    value: number;
+    [property: string]: mixed | number;
+};
+
+export type EnumValues = {
+    label: string;
+    [property: string]: mixed | string;
+};
+
+export type FormatException = {
+    count: number;
+    [property: string]: mixed | number;
+};
+
+export type RegExp = {
+    active: boolean;
+    [property: string]: mixed | boolean;
+};
+
+export type Status =
+      "ready"
+    | "done";
+
+// Converts JSON strings to/from your types
+// and asserts the results of JSON.parse at runtime
+function toTopLevel(json: string): TopLevel {
+    return cast(JSON.parse(json), r("TopLevel"));
+}
+
+function topLevelToJson(value: TopLevel): string {
+    return JSON.stringify(uncast(value, r("TopLevel")), null, 2);
+}
+
+function invalidValue(typ: any, val: any, key: any, parent: any = '') {
+    const prettyTyp = prettyTypeName(typ);
+    const parentText = parent ? ` on ${parent}` : '';
+    const keyText = key ? ` for key "${key}"` : '';
+    throw Error(`Invalid value${keyText}${parentText}. Expected ${prettyTyp} but got ${JSON.stringify(val)}`);
+}
+
+function prettyTypeName(typ: any): string {
+    if (Array.isArray(typ)) {
+        if (typ.length === 2 && typ[0] === undefined) {
+            return `an optional ${prettyTypeName(typ[1])}`;
+        } else {
+            return `one of [${typ.map(a => { return prettyTypeName(a); }).join(", ")}]`;
+        }
+    } else if (typeof typ === "object" && typ.literal !== undefined) {
+        return typ.literal;
+    } else {
+        return typeof typ;
+    }
+}
+
+function jsonToJSProps(typ: any): any {
+    if (typ.jsonToJS === undefined) {
+        const map: any = {};
+        typ.props.forEach((p: any) => map[p.json] = { key: p.js, typ: p.typ });
+        typ.jsonToJS = map;
+    }
+    return typ.jsonToJS;
+}
+
+function jsToJSONProps(typ: any): any {
+    if (typ.jsToJSON === undefined) {
+        const map: any = {};
+        typ.props.forEach((p: any) => map[p.js] = { key: p.json, typ: p.typ });
+        typ.jsToJSON = map;
+    }
+    return typ.jsToJSON;
+}
+
+function transform(val: any, typ: any, getProps: any, key: any = '', parent: any = ''): any {
+    function transformPrimitive(typ: string, val: any): any {
+        if (typeof typ === typeof val) return val;
+        return invalidValue(typ, val, key, parent);
+    }
+
+    function transformUnion(typs: any[], val: any): any {
+        // val must validate against one typ in typs
+        const l = typs.length;
+        for (let i = 0; i < l; i++) {
+            const typ = typs[i];
+            try {
+                return transform(val, typ, getProps);
+            } catch (_) {}
+        }
+        return invalidValue(typs, val, key, parent);
+    }
+
+    function transformEnum(cases: string[], val: any): any {
+        if (cases.indexOf(val) !== -1) return val;
+        return invalidValue(cases.map(a => { return l(a); }), val, key, parent);
+    }
+
+    function transformArray(typ: any, val: any): any {
+        // val must be an array with no invalid elements
+        if (!Array.isArray(val)) return invalidValue(l("array"), val, key, parent);
+
+        return val.map(el => transform(el, typ, getProps));
+    }
+
+    function transformDate(val: any): any {
+        if (val === null) {
+            return null;
+        }
+        const d = new Date(val);
+        if (isNaN(d.valueOf())) {
+            return invalidValue(l("Date"), val, key, parent);
+        }
+        return d;
+    }
+
+    function transformObject(props: { [k: string]: any }, additional: any, val: any): any {
+        if (val === null || typeof val !== "object" || Array.isArray(val)) {
+            return invalidValue(l(ref || "object"), val, key, parent);
+        }
+        const result: any = {};
+        Object.getOwnPropertyNames(props).forEach(key => {
+            const prop = props[key];
+            const v = Object.prototype.hasOwnProperty.call(val, key) ? val[key] : undefined;
+            result[prop.key] = transform(v, prop.typ, getProps, key, ref);
+        });
+        Object.getOwnPropertyNames(val).forEach(key => {
+            if (!Object.prototype.hasOwnProperty.call(props, key)) {
+                result[key] = transform(val[key], additional, getProps, key, ref);
+            }
+        });
+        return result;
+    }
+
+    if (typ === "any") return val;
+    if (typ === null) {
+        if (val === null) return val;
+        return invalidValue(typ, val, key, parent);
+    }
+    if (typ === false) return invalidValue(typ, val, key, parent);
+    let ref: any = undefined;
+    while (typeof typ === "object" && typ.ref !== undefined) {
+        ref = typ.ref;
+        typ = typeMap[typ.ref];
+    }
+    if (Array.isArray(typ)) return transformEnum(typ, val);
+    if (typeof typ === "object") {
+        return typ.hasOwnProperty("pattern")      ? typeof val === "string" && new RegExp(typ.pattern).test(val) ? val : invalidValue(typ, val, key, parent)
+            : typ.hasOwnProperty("string")       ? typeof val === "string" && (typ.min === undefined || val.length >= typ.min) && (typ.max === undefined || val.length <= typ.max) ? transform(val, typ.string, getProps, key, parent) : invalidValue(typ, val, key, parent)
+            : typ.hasOwnProperty("number")       ? typeof val === "number" && (typ.min === undefined || val >= typ.min) && (typ.max === undefined || val <= typ.max) ? transform(val, typ.number, getProps, key, parent) : invalidValue(typ, val, key, parent)
+            : typ.hasOwnProperty("integer")      ? typeof val === "number" && val % 1 === 0 ? val : invalidValue(l("integer"), val, key, parent)
+            : typ.hasOwnProperty("unionMembers") ? transformUnion(typ.unionMembers, val)
+            : typ.hasOwnProperty("arrayItems")    ? transformArray(typ.arrayItems, val)
+            : typ.hasOwnProperty("props")         ? transformObject(getProps(typ), typ.additional, val)
+            : invalidValue(typ, val, key, parent);
+    }
+    // Numbers can be parsed by Date but shouldn't be.
+    if (typ === Date && typeof val !== "number") return transformDate(val);
+    return transformPrimitive(typ, val);
+}
+
+function cast<T>(val: any, typ: any): T {
+    return transform(val, typ, jsonToJSProps);
+}
+
+function uncast<T>(val: T, typ: any): any {
+    return transform(val, typ, jsToJSONProps);
+}
+
+function l(typ: any) {
+    return { literal: typ };
+}
+
+function a(typ: any) {
+    return { arrayItems: typ };
+}
+
+function i(typ: any) {
+    return { integer: typ };
+}
+
+function p(pattern: any) {
+    return { pattern };
+}
+
+function s(typ: any, min: any, max: any) {
+    return { string: typ, min, max };
+}
+
+function n(typ: any, min: any, max: any) {
+    return { number: typ, min, max };
+}
+
+function u(...typs: any[]) {
+    return { unionMembers: typs };
+}
+
+function o(props: any[], additional: any) {
+    return { props, additional };
+}
+
+function m(additional: any) {
+    const props: any[] = [];
+    return { props, additional };
+}
+
+function r(name: string) {
+    return { ref: name };
+}
+
+const typeMap: any = {
+    "TopLevel": o([
+        { json: "code", js: "code", typ: s(p("^[a-z]+$"), 1, undefined) },
+        { json: "dateTime", js: "dateTime", typ: r("DateTime") },
+        { json: "enumValues", js: "enumValues", typ: r("EnumValues") },
+        { json: "formatException", js: "formatException", typ: r("FormatException") },
+        { json: "regExp", js: "regExp", typ: r("RegExp") },
+        { json: "status", js: "status", typ: r("Status") },
+        { json: "timestamp", js: "timestamp", typ: Date },
+    ], false),
+    "DateTime": o([
+        { json: "value", js: "value", typ: i(0) },
+    ], "any"),
+    "EnumValues": o([
+        { json: "label", js: "label", typ: "" },
+    ], "any"),
+    "FormatException": o([
+        { json: "count", js: "count", typ: i(0) },
+    ], "any"),
+    "RegExp": o([
+        { json: "active", js: "active", typ: true },
+    ], "any"),
+    "Status": [
+        "ready",
+        "done",
+    ],
+};
+
+module.exports = {
+    "topLevelToJson": topLevelToJson,
+    "toTopLevel": toTopLevel,
+};
diff --git a/head/schema-golang/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.go b/head/schema-golang/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.go
new file mode 100644
index 0000000..4442a82
--- /dev/null
+++ b/head/schema-golang/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.go
@@ -0,0 +1,66 @@
+// Code generated from JSON Schema using quicktype. DO NOT EDIT.
+// To parse and unparse this JSON data, add this code to your project and do:
+//
+//    topLevel, err := UnmarshalTopLevel(bytes)
+//    bytes, err = topLevel.Marshal()
+
+package main
+
+import "time"
+
+import "encoding/json"
+
+func UnmarshalTopLevel(data []byte) (TopLevel, error) {
+	var r TopLevel
+	err := json.Unmarshal(data, &r)
+	return r, err
+}
+
+func (r *TopLevel) Marshal() ([]byte, error) {
+	return json.Marshal(r)
+}
+
+type TopLevel struct {
+	Code            string          `json:"code"`
+	DateTime        DateTime        `json:"dateTime"`
+	EnumValues      EnumValues      `json:"enumValues"`
+	FormatException FormatException `json:"formatException"`
+	RegExp          RegExp          `json:"regExp"`
+	Status          Status          `json:"status"`
+	Timestamp       time.Time       `json:"timestamp"`
+}
+
+type DateTime struct {
+	Value int64 `json:"value"`
+}
+
+type EnumValues struct {
+	Label string `json:"label"`
+}
+
+type FormatException struct {
+	Count int64 `json:"count"`
+}
+
+type RegExp struct {
+	Active bool `json:"active"`
+}
+
+type Status string
+
+const (
+	Ready Status = "ready"
+	Done  Status = "done"
+)
+
+type invalidStatus string
+func (x invalidStatus) Error() string { return "invalid Status: " + string(x) }
+
+func (x *Status) UnmarshalJSON(data []byte) error {
+	var value string
+	if err := json.Unmarshal(data, &value); err != nil { return err }
+	switch Status(value) {
+	case Ready, Done: *x = Status(value); return nil
+	}
+	return invalidStatus(value)
+}
diff --git a/head/schema-haskell/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.hs b/head/schema-haskell/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.hs
new file mode 100644
index 0000000..5d02612
--- /dev/null
+++ b/head/schema-haskell/test/inputs/schema/dart-runtime-type-names.schema/default/QuickType.hs
@@ -0,0 +1,124 @@
+{-# LANGUAGE StrictData #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module QuickType
+    ( QuickType (..)
+    , DateTime (..)
+    , EnumValues (..)
+    , FormatException (..)
+    , RegExp (..)
+    , Status (..)
+    , decodeTopLevel
+    ) where
+
+import Data.Aeson
+import Data.Aeson.Types (emptyObject)
+import Data.ByteString.Lazy (ByteString)
+import Data.HashMap.Strict (HashMap)
+import Data.Text (Text)
+
+data QuickType = QuickType
+    { codeQuickType :: Text
+    , dateTimeQuickType :: DateTime
+    , enumValuesQuickType :: EnumValues
+    , formatExceptionQuickType :: FormatException
+    , regExpQuickType :: RegExp
+    , statusQuickType :: Status
+    , timestampQuickType :: Text
+    } deriving (Show)
+
+data DateTime = DateTime
+    { valueDateTime :: Int
+    } deriving (Show)
+
+data EnumValues = EnumValues
+    { labelEnumValues :: Text
+    } deriving (Show)
+
+data FormatException = FormatException
+    { countFormatException :: Int
+    } deriving (Show)
+
+data RegExp = RegExp
+    { activeRegExp :: Bool
+    } deriving (Show)
+
+data Status
+    = ReadyStatus
+    | DoneStatus
+    deriving (Show)
+
+decodeTopLevel :: ByteString -> Maybe QuickType
+decodeTopLevel = decode
+
+instance ToJSON QuickType where
+    toJSON (QuickType codeQuickType dateTimeQuickType enumValuesQuickType formatExceptionQuickType regExpQuickType statusQuickType timestampQuickType) =
+        object
+        [ "code" .= codeQuickType
+        , "dateTime" .= dateTimeQuickType
+        , "enumValues" .= enumValuesQuickType
+        , "formatException" .= formatExceptionQuickType
+        , "regExp" .= regExpQuickType
+        , "status" .= statusQuickType
+        , "timestamp" .= timestampQuickType
+        ]
+
+instance FromJSON QuickType where
+    parseJSON (Object v) = QuickType
+        <$> v .: "code"
+        <*> v .: "dateTime"
+        <*> v .: "enumValues"
+        <*> v .: "formatException"
+        <*> v .: "regExp"
+        <*> v .: "status"
+        <*> v .: "timestamp"
+
+instance ToJSON DateTime where
+    toJSON (DateTime valueDateTime) =
+        object
+        [ "value" .= valueDateTime
+        ]
+
+instance FromJSON DateTime where
+    parseJSON (Object v) = DateTime
+        <$> v .: "value"
+
+instance ToJSON EnumValues where
+    toJSON (EnumValues labelEnumValues) =
+        object
+        [ "label" .= labelEnumValues
+        ]
+
+instance FromJSON EnumValues where
+    parseJSON (Object v) = EnumValues
+        <$> v .: "label"
+
+instance ToJSON FormatException where
+    toJSON (FormatException countFormatException) =
+        object
+        [ "count" .= countFormatException
+        ]
+
+instance FromJSON FormatException where
+    parseJSON (Object v) = FormatException
+        <$> v .: "count"
+
+instance ToJSON RegExp where
+    toJSON (RegExp activeRegExp) =
+        object
+        [ "active" .= activeRegExp
+        ]
+
+instance FromJSON RegExp where
+    parseJSON (Object v) = RegExp
+        <$> v .: "active"
+
+instance ToJSON Status where
+    toJSON ReadyStatus = "ready"
+    toJSON DoneStatus = "done"
+
+instance FromJSON Status where
+    parseJSON = withText "Status" parseText
+        where
+            parseText "ready" = return ReadyStatus
+            parseText "done" = return DoneStatus
diff --git a/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Converter.java b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Converter.java
new file mode 100644
index 0000000..d243dc1
--- /dev/null
+++ b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Converter.java
@@ -0,0 +1,103 @@
+// To use this code, add the following Maven dependency to your project:
+//
+//
+//     com.fasterxml.jackson.core     : jackson-databind          : 2.9.0
+//     com.fasterxml.jackson.datatype : jackson-datatype-jsr310   : 2.9.0
+//
+// Import this package:
+//
+//     import io.quicktype.Converter;
+//
+// Then you can deserialize a JSON string with
+//
+//     TopLevel data = Converter.fromJsonString(jsonString);
+
+package io.quicktype;
+
+import java.io.IOException;
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import java.util.*;
+import java.time.LocalDate;
+import java.time.OffsetDateTime;
+import java.time.OffsetTime;
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeFormatterBuilder;
+import java.time.temporal.ChronoField;
+
+public class Converter {
+    // Date-time helpers
+
+    private static final DateTimeFormatter DATE_TIME_FORMATTER = new DateTimeFormatterBuilder()
+            .appendOptional(DateTimeFormatter.ISO_DATE_TIME)
+            .appendOptional(DateTimeFormatter.ISO_OFFSET_DATE_TIME)
+            .appendOptional(DateTimeFormatter.ISO_INSTANT)
+            .appendOptional(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SX"))
+            .appendOptional(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ssX"))
+            .appendOptional(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"))
+            .toFormatter()
+            .withZone(ZoneOffset.UTC);
+
+    public static OffsetDateTime parseDateTimeString(String str) {
+        return ZonedDateTime.from(Converter.DATE_TIME_FORMATTER.parse(str)).toOffsetDateTime();
+    }
+
+    private static final DateTimeFormatter TIME_FORMATTER = new DateTimeFormatterBuilder()
+            .appendOptional(DateTimeFormatter.ISO_TIME)
+            .appendOptional(DateTimeFormatter.ISO_OFFSET_TIME)
+            .parseDefaulting(ChronoField.YEAR, 2020)
+            .parseDefaulting(ChronoField.MONTH_OF_YEAR, 1)
+            .parseDefaulting(ChronoField.DAY_OF_MONTH, 1)
+            .toFormatter()
+            .withZone(ZoneOffset.UTC);
+
+    public static OffsetTime parseTimeString(String str) {
+        return ZonedDateTime.from(Converter.TIME_FORMATTER.parse(str)).toOffsetDateTime().toOffsetTime();
+    }
+    // Serialize/deserialize helpers
+
+    public static TopLevel fromJsonString(String json) throws IOException {
+        return getObjectReader().readValue(json);
+    }
+
+    public static String toJsonString(TopLevel obj) throws JsonProcessingException {
+        return getObjectWriter().writeValueAsString(obj);
+    }
+
+    private static ObjectReader reader;
+    private static ObjectWriter writer;
+
+    private static void instantiateMapper() {
+        ObjectMapper mapper = new ObjectMapper();
+        mapper.findAndRegisterModules();
+        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+        mapper.configure(DeserializationFeature.ACCEPT_FLOAT_AS_INT, false);
+        mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
+        SimpleModule module = new SimpleModule();
+        module.addDeserializer(OffsetDateTime.class, new JsonDeserializer<OffsetDateTime>() {
+            @Override
+            public OffsetDateTime deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
+                String value = jsonParser.getText();
+                return Converter.parseDateTimeString(value);
+            }
+        });
+        mapper.registerModule(module);
+        reader = mapper.readerFor(TopLevel.class);
+        writer = mapper.writerFor(TopLevel.class);
+    }
+
+    private static ObjectReader getObjectReader() {
+        if (reader == null) instantiateMapper();
+        return reader;
+    }
+
+    private static ObjectWriter getObjectWriter() {
+        if (writer == null) instantiateMapper();
+        return writer;
+    }
+}
diff --git a/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/DateTime.java b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/DateTime.java
new file mode 100644
index 0000000..9d358b7
--- /dev/null
+++ b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/DateTime.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class DateTime {
+    private long value;
+
+    @JsonProperty("value")
+    public long getValue() { return value; }
+    @JsonProperty("value")
+    public void setValue(long value) { this.value = value; }
+}
diff --git a/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/EnumValues.java b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/EnumValues.java
new file mode 100644
index 0000000..393b64d
--- /dev/null
+++ b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/EnumValues.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class EnumValues {
+    private String label;
+
+    @JsonProperty("label")
+    public String getLabel() { return label; }
+    @JsonProperty("label")
+    public void setLabel(String value) { this.label = value; }
+}
diff --git a/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/FormatException.java b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/FormatException.java
new file mode 100644
index 0000000..35cb026
--- /dev/null
+++ b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/FormatException.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class FormatException {
+    private long count;
+
+    @JsonProperty("count")
+    public long getCount() { return count; }
+    @JsonProperty("count")
+    public void setCount(long value) { this.count = value; }
+}
diff --git a/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/RegExp.java b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/RegExp.java
new file mode 100644
index 0000000..254c5e1
--- /dev/null
+++ b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/RegExp.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class RegExp {
+    private boolean active;
+
+    @JsonProperty("active")
+    public boolean getActive() { return active; }
+    @JsonProperty("active")
+    public void setActive(boolean value) { this.active = value; }
+}
diff --git a/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Status.java b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Status.java
new file mode 100644
index 0000000..5932577
--- /dev/null
+++ b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Status.java
@@ -0,0 +1,24 @@
+package io.quicktype;
+
+import java.io.IOException;
+import com.fasterxml.jackson.annotation.*;
+
+public enum Status {
+    READY, DONE;
+
+    @JsonValue
+    public String toValue() {
+        switch (this) {
+            case READY: return "ready";
+            case DONE: return "done";
+        }
+        return null;
+    }
+
+    @JsonCreator
+    public static Status forValue(String value) throws IOException {
+        if (value.equals("ready")) return READY;
+        if (value.equals("done")) return DONE;
+        throw new IOException("Cannot deserialize Status");
+    }
+}
diff --git a/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/TopLevel.java b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/TopLevel.java
new file mode 100644
index 0000000..6bd5ef6
--- /dev/null
+++ b/head/schema-java/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/TopLevel.java
@@ -0,0 +1,49 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+import java.time.OffsetDateTime;
+
+public class TopLevel {
+    private String code;
+    private DateTime dateTime;
+    private EnumValues enumValues;
+    private FormatException formatException;
+    private RegExp regExp;
+    private Status status;
+    private OffsetDateTime timestamp;
+
+    @JsonProperty("code")
+    public String getCode() { return code; }
+    @JsonProperty("code")
+    public void setCode(String value) { this.code = value; }
+
+    @JsonProperty("dateTime")
+    public DateTime getDateTime() { return dateTime; }
+    @JsonProperty("dateTime")
+    public void setDateTime(DateTime value) { this.dateTime = value; }
+
+    @JsonProperty("enumValues")
+    public EnumValues getEnumValues() { return enumValues; }
+    @JsonProperty("enumValues")
+    public void setEnumValues(EnumValues value) { this.enumValues = value; }
+
+    @JsonProperty("formatException")
+    public FormatException getFormatException() { return formatException; }
+    @JsonProperty("formatException")
+    public void setFormatException(FormatException value) { this.formatException = value; }
+
+    @JsonProperty("regExp")
+    public RegExp getRegExp() { return regExp; }
+    @JsonProperty("regExp")
+    public void setRegExp(RegExp value) { this.regExp = value; }
+
+    @JsonProperty("status")
+    public Status getStatus() { return status; }
+    @JsonProperty("status")
+    public void setStatus(Status value) { this.status = value; }
+
+    @JsonProperty("timestamp")
+    public OffsetDateTime getTimestamp() { return timestamp; }
+    @JsonProperty("timestamp")
+    public void setTimestamp(OffsetDateTime value) { this.timestamp = value; }
+}
diff --git a/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Converter.java b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Converter.java
new file mode 100644
index 0000000..aeaa704
--- /dev/null
+++ b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Converter.java
@@ -0,0 +1,124 @@
+// To use this code, add the following Maven dependency to your project:
+//
+//
+//     com.fasterxml.jackson.core     : jackson-databind          : 2.9.0
+//
+//
+// Import this package:
+//
+//     import io.quicktype.Converter;
+//
+// Then you can deserialize a JSON string with
+//
+//     TopLevel data = Converter.fromJsonString(jsonString);
+
+package io.quicktype;
+
+import java.io.IOException;
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import java.util.*;
+import java.util.Date;
+import java.text.SimpleDateFormat;
+
+public class Converter {
+    // Date-time helpers
+
+    private static final String[] DATE_TIME_FORMATS = {
+            "yyyy-MM-dd'T'HH:mm:ss.SX",
+            "yyyy-MM-dd'T'HH:mm:ss.S",
+            "yyyy-MM-dd'T'HH:mm:ssX",
+            "yyyy-MM-dd'T'HH:mm:ss",
+            "yyyy-MM-dd HH:mm:ss.SX",
+            "yyyy-MM-dd HH:mm:ss.S",
+            "yyyy-MM-dd HH:mm:ssX",
+            "yyyy-MM-dd HH:mm:ss",
+            "HH:mm:ss.SZ",
+            "HH:mm:ss.S",
+            "HH:mm:ssZ",
+            "HH:mm:ss",
+            "yyyy-MM-dd",
+    };
+
+    public static Date parseAllDateTimeString(String str) {
+        str = str.replaceFirst("(\\.\\d{3})\\d+", "$1");
+        for (String format : DATE_TIME_FORMATS) {
+            try {
+                return new SimpleDateFormat(format).parse(str);
+            } catch (Exception ex) {
+                // Ignored
+            }
+        }
+        return null;
+    }
+
+    public static String serializeDateTime(Date datetime) {
+        return new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ssZ").format(datetime);
+    }
+
+    public static String serializeDate(Date datetime) {
+        return new SimpleDateFormat("yyyy-MM-dd").format(datetime);
+    }
+
+    public static String serializeTime(Date datetime) {
+        return new SimpleDateFormat("hh:mm:ssZ").format(datetime);
+    }
+    // Serialize/deserialize helpers
+
+    public static TopLevel fromJsonString(String json) throws IOException {
+        return getObjectReader().readValue(json);
+    }
+
+    public static String toJsonString(TopLevel obj) throws JsonProcessingException {
+        return getObjectWriter().writeValueAsString(obj);
+    }
+
+    private static ObjectReader reader;
+    private static ObjectWriter writer;
+
+    private static void instantiateMapper() {
+        ObjectMapper mapper = new ObjectMapper();
+        mapper.findAndRegisterModules();
+        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+        mapper.configure(DeserializationFeature.ACCEPT_FLOAT_AS_INT, false);
+        mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
+        SimpleModule module = new SimpleModule();
+        module.addDeserializer(Date.class, new JsonDeserializer<Date>() {
+            @Override
+            public Date deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
+                String value = jsonParser.getText();
+                return Converter.parseAllDateTimeString(value);
+            }
+        });
+        module.addDeserializer(Date.class, new JsonDeserializer<Date>() {
+            @Override
+            public Date deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
+                String value = jsonParser.getText();
+                return Converter.parseAllDateTimeString(value);
+            }
+        });
+        module.addDeserializer(Date.class, new JsonDeserializer<Date>() {
+            @Override
+            public Date deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
+                String value = jsonParser.getText();
+                return Converter.parseAllDateTimeString(value);
+            }
+        });
+        mapper.registerModule(module);
+        reader = mapper.readerFor(TopLevel.class);
+        writer = mapper.writerFor(TopLevel.class);
+    }
+
+    private static ObjectReader getObjectReader() {
+        if (reader == null) instantiateMapper();
+        return reader;
+    }
+
+    private static ObjectWriter getObjectWriter() {
+        if (writer == null) instantiateMapper();
+        return writer;
+    }
+}
diff --git a/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/DateTime.java b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/DateTime.java
new file mode 100644
index 0000000..9d358b7
--- /dev/null
+++ b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/DateTime.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class DateTime {
+    private long value;
+
+    @JsonProperty("value")
+    public long getValue() { return value; }
+    @JsonProperty("value")
+    public void setValue(long value) { this.value = value; }
+}
diff --git a/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/EnumValues.java b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/EnumValues.java
new file mode 100644
index 0000000..393b64d
--- /dev/null
+++ b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/EnumValues.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class EnumValues {
+    private String label;
+
+    @JsonProperty("label")
+    public String getLabel() { return label; }
+    @JsonProperty("label")
+    public void setLabel(String value) { this.label = value; }
+}
diff --git a/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/FormatException.java b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/FormatException.java
new file mode 100644
index 0000000..35cb026
--- /dev/null
+++ b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/FormatException.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class FormatException {
+    private long count;
+
+    @JsonProperty("count")
+    public long getCount() { return count; }
+    @JsonProperty("count")
+    public void setCount(long value) { this.count = value; }
+}
diff --git a/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/RegExp.java b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/RegExp.java
new file mode 100644
index 0000000..254c5e1
--- /dev/null
+++ b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/RegExp.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class RegExp {
+    private boolean active;
+
+    @JsonProperty("active")
+    public boolean getActive() { return active; }
+    @JsonProperty("active")
+    public void setActive(boolean value) { this.active = value; }
+}
diff --git a/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Status.java b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Status.java
new file mode 100644
index 0000000..5932577
--- /dev/null
+++ b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Status.java
@@ -0,0 +1,24 @@
+package io.quicktype;
+
+import java.io.IOException;
+import com.fasterxml.jackson.annotation.*;
+
+public enum Status {
+    READY, DONE;
+
+    @JsonValue
+    public String toValue() {
+        switch (this) {
+            case READY: return "ready";
+            case DONE: return "done";
+        }
+        return null;
+    }
+
+    @JsonCreator
+    public static Status forValue(String value) throws IOException {
+        if (value.equals("ready")) return READY;
+        if (value.equals("done")) return DONE;
+        throw new IOException("Cannot deserialize Status");
+    }
+}
diff --git a/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/TopLevel.java b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/TopLevel.java
new file mode 100644
index 0000000..f6ddead
--- /dev/null
+++ b/head/schema-java-datetime-legacy/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/TopLevel.java
@@ -0,0 +1,51 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+import java.util.Date;
+
+public class TopLevel {
+    private String code;
+    private DateTime dateTime;
+    private EnumValues enumValues;
+    private FormatException formatException;
+    private RegExp regExp;
+    private Status status;
+    private Date timestamp;
+
+    @JsonProperty("code")
+    public String getCode() { return code; }
+    @JsonProperty("code")
+    public void setCode(String value) { this.code = value; }
+
+    @JsonProperty("dateTime")
+    public DateTime getDateTime() { return dateTime; }
+    @JsonProperty("dateTime")
+    public void setDateTime(DateTime value) { this.dateTime = value; }
+
+    @JsonProperty("enumValues")
+    public EnumValues getEnumValues() { return enumValues; }
+    @JsonProperty("enumValues")
+    public void setEnumValues(EnumValues value) { this.enumValues = value; }
+
+    @JsonProperty("formatException")
+    public FormatException getFormatException() { return formatException; }
+    @JsonProperty("formatException")
+    public void setFormatException(FormatException value) { this.formatException = value; }
+
+    @JsonProperty("regExp")
+    public RegExp getRegExp() { return regExp; }
+    @JsonProperty("regExp")
+    public void setRegExp(RegExp value) { this.regExp = value; }
+
+    @JsonProperty("status")
+    public Status getStatus() { return status; }
+    @JsonProperty("status")
+    public void setStatus(Status value) { this.status = value; }
+
+    @JsonProperty("timestamp")
+    @JsonFormat(pattern = "yyyy-MM-dd'T'HH:mm:ss.SSSX", timezone = "UTC")
+    public Date getTimestamp() { return timestamp; }
+    @JsonProperty("timestamp")
+    @JsonFormat(pattern = "yyyy-MM-dd'T'HH:mm:ss.SSSX", timezone = "UTC")
+    public void setTimestamp(Date value) { this.timestamp = value; }
+}
diff --git a/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Converter.java b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Converter.java
new file mode 100644
index 0000000..d243dc1
--- /dev/null
+++ b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Converter.java
@@ -0,0 +1,103 @@
+// To use this code, add the following Maven dependency to your project:
+//
+//
+//     com.fasterxml.jackson.core     : jackson-databind          : 2.9.0
+//     com.fasterxml.jackson.datatype : jackson-datatype-jsr310   : 2.9.0
+//
+// Import this package:
+//
+//     import io.quicktype.Converter;
+//
+// Then you can deserialize a JSON string with
+//
+//     TopLevel data = Converter.fromJsonString(jsonString);
+
+package io.quicktype;
+
+import java.io.IOException;
+import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import java.util.*;
+import java.time.LocalDate;
+import java.time.OffsetDateTime;
+import java.time.OffsetTime;
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeFormatterBuilder;
+import java.time.temporal.ChronoField;
+
+public class Converter {
+    // Date-time helpers
+
+    private static final DateTimeFormatter DATE_TIME_FORMATTER = new DateTimeFormatterBuilder()
+            .appendOptional(DateTimeFormatter.ISO_DATE_TIME)
+            .appendOptional(DateTimeFormatter.ISO_OFFSET_DATE_TIME)
+            .appendOptional(DateTimeFormatter.ISO_INSTANT)
+            .appendOptional(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SX"))
+            .appendOptional(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ssX"))
+            .appendOptional(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"))
+            .toFormatter()
+            .withZone(ZoneOffset.UTC);
+
+    public static OffsetDateTime parseDateTimeString(String str) {
+        return ZonedDateTime.from(Converter.DATE_TIME_FORMATTER.parse(str)).toOffsetDateTime();
+    }
+
+    private static final DateTimeFormatter TIME_FORMATTER = new DateTimeFormatterBuilder()
+            .appendOptional(DateTimeFormatter.ISO_TIME)
+            .appendOptional(DateTimeFormatter.ISO_OFFSET_TIME)
+            .parseDefaulting(ChronoField.YEAR, 2020)
+            .parseDefaulting(ChronoField.MONTH_OF_YEAR, 1)
+            .parseDefaulting(ChronoField.DAY_OF_MONTH, 1)
+            .toFormatter()
+            .withZone(ZoneOffset.UTC);
+
+    public static OffsetTime parseTimeString(String str) {
+        return ZonedDateTime.from(Converter.TIME_FORMATTER.parse(str)).toOffsetDateTime().toOffsetTime();
+    }
+    // Serialize/deserialize helpers
+
+    public static TopLevel fromJsonString(String json) throws IOException {
+        return getObjectReader().readValue(json);
+    }
+
+    public static String toJsonString(TopLevel obj) throws JsonProcessingException {
+        return getObjectWriter().writeValueAsString(obj);
+    }
+
+    private static ObjectReader reader;
+    private static ObjectWriter writer;
+
+    private static void instantiateMapper() {
+        ObjectMapper mapper = new ObjectMapper();
+        mapper.findAndRegisterModules();
+        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+        mapper.configure(DeserializationFeature.ACCEPT_FLOAT_AS_INT, false);
+        mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
+        SimpleModule module = new SimpleModule();
+        module.addDeserializer(OffsetDateTime.class, new JsonDeserializer<OffsetDateTime>() {
+            @Override
+            public OffsetDateTime deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
+                String value = jsonParser.getText();
+                return Converter.parseDateTimeString(value);
+            }
+        });
+        mapper.registerModule(module);
+        reader = mapper.readerFor(TopLevel.class);
+        writer = mapper.writerFor(TopLevel.class);
+    }
+
+    private static ObjectReader getObjectReader() {
+        if (reader == null) instantiateMapper();
+        return reader;
+    }
+
+    private static ObjectWriter getObjectWriter() {
+        if (writer == null) instantiateMapper();
+        return writer;
+    }
+}
diff --git a/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/DateTime.java b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/DateTime.java
new file mode 100644
index 0000000..9d358b7
--- /dev/null
+++ b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/DateTime.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class DateTime {
+    private long value;
+
+    @JsonProperty("value")
+    public long getValue() { return value; }
+    @JsonProperty("value")
+    public void setValue(long value) { this.value = value; }
+}
diff --git a/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/EnumValues.java b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/EnumValues.java
new file mode 100644
index 0000000..393b64d
--- /dev/null
+++ b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/EnumValues.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class EnumValues {
+    private String label;
+
+    @JsonProperty("label")
+    public String getLabel() { return label; }
+    @JsonProperty("label")
+    public void setLabel(String value) { this.label = value; }
+}
diff --git a/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/FormatException.java b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/FormatException.java
new file mode 100644
index 0000000..35cb026
--- /dev/null
+++ b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/FormatException.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class FormatException {
+    private long count;
+
+    @JsonProperty("count")
+    public long getCount() { return count; }
+    @JsonProperty("count")
+    public void setCount(long value) { this.count = value; }
+}
diff --git a/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/RegExp.java b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/RegExp.java
new file mode 100644
index 0000000..254c5e1
--- /dev/null
+++ b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/RegExp.java
@@ -0,0 +1,12 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+
+public class RegExp {
+    private boolean active;
+
+    @JsonProperty("active")
+    public boolean getActive() { return active; }
+    @JsonProperty("active")
+    public void setActive(boolean value) { this.active = value; }
+}
diff --git a/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Status.java b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Status.java
new file mode 100644
index 0000000..5932577
--- /dev/null
+++ b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/Status.java
@@ -0,0 +1,24 @@
+package io.quicktype;
+
+import java.io.IOException;
+import com.fasterxml.jackson.annotation.*;
+
+public enum Status {
+    READY, DONE;
+
+    @JsonValue
+    public String toValue() {
+        switch (this) {
+            case READY: return "ready";
+            case DONE: return "done";
+        }
+        return null;
+    }
+
+    @JsonCreator
+    public static Status forValue(String value) throws IOException {
+        if (value.equals("ready")) return READY;
+        if (value.equals("done")) return DONE;
+        throw new IOException("Cannot deserialize Status");
+    }
+}
diff --git a/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/TopLevel.java b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/TopLevel.java
new file mode 100644
index 0000000..6bd5ef6
--- /dev/null
+++ b/head/schema-java-lombok/test/inputs/schema/dart-runtime-type-names.schema/default/src/main/java/io/quicktype/TopLevel.java
@@ -0,0 +1,49 @@
+package io.quicktype;
+
+import com.fasterxml.jackson.annotation.*;
+import java.time.OffsetDateTime;
+
+public class TopLevel {
+    private String code;
+    private DateTime dateTime;
+    private EnumValues enumValues;
+    private FormatException formatException;
+    private RegExp regExp;
+    private Status status;
+    private OffsetDateTime timestamp;
+
+    @JsonProperty("code")
+    public String getCode() { return code; }
+    @JsonProperty("code")
+    public void setCode(String value) { this.code = value; }
+
+    @JsonProperty("dateTime")
+    public DateTime getDateTime() { return dateTime; }
+    @JsonProperty("dateTime")
+    public void setDateTime(DateTime value) { this.dateTime = value; }
+
+    @JsonProperty("enumValues")
+    public EnumValues getEnumValues() { return enumValues; }
+    @JsonProperty("enumValues")
+    public void setEnumValues(EnumValues value) { this.enumValues = value; }
+
+    @JsonProperty("formatException")
+    public FormatException getFormatException() { return formatException; }
+    @JsonProperty("formatException")
+    public void setFormatException(FormatException value) { this.formatException = value; }
+
+    @JsonProperty("regExp")
+    public RegExp getRegExp() { return regExp; }
+    @JsonProperty("regExp")
+    public void setRegExp(RegExp value) { this.regExp = value; }
+
+    @JsonProperty("status")
+    public Status getStatus() { return status; }
+    @JsonProperty("status")
+    public void setStatus(Status value) { this.status = value; }
+
+    @JsonProperty("timestamp")
+    public OffsetDateTime getTimestamp() { return timestamp; }
+    @JsonProperty("timestamp")
+    public void setTimestamp(OffsetDateTime value) { this.timestamp = value; }
+}
diff --git a/head/schema-javascript/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.js b/head/schema-javascript/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.js
new file mode 100644
index 0000000..c7bcd27
--- /dev/null
+++ b/head/schema-javascript/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.js
@@ -0,0 +1,225 @@
+// To parse this data:
+//
+//   const Convert = require("./TopLevel");
+//
+//   const topLevel = Convert.toTopLevel(json);
+//
+// These functions will throw an error if the JSON doesn't
+// match the expected interface, even if the JSON is valid.
+
+// Converts JSON strings to/from your types
+// and asserts the results of JSON.parse at runtime
+function toTopLevel(json) {
+    return cast(JSON.parse(json), r("TopLevel"));
+}
+
+function topLevelToJson(value) {
+    return JSON.stringify(uncast(value, r("TopLevel")), null, 2);
+}
+
+function invalidValue(typ, val, key, parent = '') {
+    const prettyTyp = prettyTypeName(typ);
+    const parentText = parent ? ` on ${parent}` : '';
+    const keyText = key ? ` for key "${key}"` : '';
+    throw Error(`Invalid value${keyText}${parentText}. Expected ${prettyTyp} but got ${JSON.stringify(val)}`);
+}
+
+function prettyTypeName(typ) {
+    if (Array.isArray(typ)) {
+        if (typ.length === 2 && typ[0] === undefined) {
+            return `an optional ${prettyTypeName(typ[1])}`;
+        } else {
+            return `one of [${typ.map(a => { return prettyTypeName(a); }).join(", ")}]`;
+        }
+    } else if (typeof typ === "object" && typ.literal !== undefined) {
+        return typ.literal;
+    } else {
+        return typeof typ;
+    }
+}
+
+function jsonToJSProps(typ) {
+    if (typ.jsonToJS === undefined) {
+        const map = {};
+        typ.props.forEach((p) => map[p.json] = { key: p.js, typ: p.typ });
+        typ.jsonToJS = map;
+    }
+    return typ.jsonToJS;
+}
+
+function jsToJSONProps(typ) {
+    if (typ.jsToJSON === undefined) {
+        const map = {};
+        typ.props.forEach((p) => map[p.js] = { key: p.json, typ: p.typ });
+        typ.jsToJSON = map;
+    }
+    return typ.jsToJSON;
+}
+
+function transform(val, typ, getProps, key = '', parent = '') {
+    function transformPrimitive(typ, val) {
+        if (typeof typ === typeof val) return val;
+        return invalidValue(typ, val, key, parent);
+    }
+
+    function transformUnion(typs, val) {
+        // val must validate against one typ in typs
+        const l = typs.length;
+        for (let i = 0; i < l; i++) {
+            const typ = typs[i];
+            try {
+                return transform(val, typ, getProps);
+            } catch (_) {}
+        }
+        return invalidValue(typs, val, key, parent);
+    }
+
+    function transformEnum(cases, val) {
+        if (cases.indexOf(val) !== -1) return val;
+        return invalidValue(cases.map(a => { return l(a); }), val, key, parent);
+    }
+
+    function transformArray(typ, val) {
+        // val must be an array with no invalid elements
+        if (!Array.isArray(val)) return invalidValue(l("array"), val, key, parent);
+
+        return val.map(el => transform(el, typ, getProps));
+    }
+
+    function transformDate(val) {
+        if (val === null) {
+            return null;
+        }
+        const d = new Date(val);
+        if (isNaN(d.valueOf())) {
+            return invalidValue(l("Date"), val, key, parent);
+        }
+        return d;
+    }
+
+    function transformObject(props, additional, val) {
+        if (val === null || typeof val !== "object" || Array.isArray(val)) {
+            return invalidValue(l(ref || "object"), val, key, parent);
+        }
+        const result = {};
+        Object.getOwnPropertyNames(props).forEach(key => {
+            const prop = props[key];
+            const v = Object.prototype.hasOwnProperty.call(val, key) ? val[key] : undefined;
+            result[prop.key] = transform(v, prop.typ, getProps, key, ref);
+        });
+        Object.getOwnPropertyNames(val).forEach(key => {
+            if (!Object.prototype.hasOwnProperty.call(props, key)) {
+                result[key] = transform(val[key], additional, getProps, key, ref);
+            }
+        });
+        return result;
+    }
+
+    if (typ === "any") return val;
+    if (typ === null) {
+        if (val === null) return val;
+        return invalidValue(typ, val, key, parent);
+    }
+    if (typ === false) return invalidValue(typ, val, key, parent);
+    let ref = undefined;
+    while (typeof typ === "object" && typ.ref !== undefined) {
+        ref = typ.ref;
+        typ = typeMap[typ.ref];
+    }
+    if (Array.isArray(typ)) return transformEnum(typ, val);
+    if (typeof typ === "object") {
+        return typ.hasOwnProperty("pattern")      ? typeof val === "string" && new RegExp(typ.pattern).test(val) ? val : invalidValue(typ, val, key, parent)
+            : typ.hasOwnProperty("string")       ? typeof val === "string" && (typ.min === undefined || val.length >= typ.min) && (typ.max === undefined || val.length <= typ.max) ? transform(val, typ.string, getProps, key, parent) : invalidValue(typ, val, key, parent)
+            : typ.hasOwnProperty("number")       ? typeof val === "number" && (typ.min === undefined || val >= typ.min) && (typ.max === undefined || val <= typ.max) ? transform(val, typ.number, getProps, key, parent) : invalidValue(typ, val, key, parent)
+            : typ.hasOwnProperty("integer")      ? typeof val === "number" && val % 1 === 0 ? val : invalidValue(l("integer"), val, key, parent)
+            : typ.hasOwnProperty("unionMembers") ? transformUnion(typ.unionMembers, val)
+            : typ.hasOwnProperty("arrayItems")    ? transformArray(typ.arrayItems, val)
+            : typ.hasOwnProperty("props")         ? transformObject(getProps(typ), typ.additional, val)
+            : invalidValue(typ, val, key, parent);
+    }
+    // Numbers can be parsed by Date but shouldn't be.
+    if (typ === Date && typeof val !== "number") return transformDate(val);
+    return transformPrimitive(typ, val);
+}
+
+function cast(val, typ) {
+    return transform(val, typ, jsonToJSProps);
+}
+
+function uncast(val, typ) {
+    return transform(val, typ, jsToJSONProps);
+}
+
+function l(typ) {
+    return { literal: typ };
+}
+
+function a(typ) {
+    return { arrayItems: typ };
+}
+
+function i(typ) {
+    return { integer: typ };
+}
+
+function p(pattern) {
+    return { pattern };
+}
+
+function s(typ, min, max) {
+    return { string: typ, min, max };
+}
+
+function n(typ, min, max) {
+    return { number: typ, min, max };
+}
+
+function u(...typs) {
+    return { unionMembers: typs };
+}
+
+function o(props, additional) {
+    return { props, additional };
+}
+
+function m(additional) {
+    const props = [];
+    return { props, additional };
+}
+
+function r(name) {
+    return { ref: name };
+}
+
+const typeMap = {
+    "TopLevel": o([
+        { json: "code", js: "code", typ: s(p("^[a-z]+$"), 1, undefined) },
+        { json: "dateTime", js: "dateTime", typ: r("DateTime") },
+        { json: "enumValues", js: "enumValues", typ: r("EnumValues") },
+        { json: "formatException", js: "formatException", typ: r("FormatException") },
+        { json: "regExp", js: "regExp", typ: r("RegExp") },
+        { json: "status", js: "status", typ: r("Status") },
+        { json: "timestamp", js: "timestamp", typ: Date },
+    ], false),
+    "DateTime": o([
+        { json: "value", js: "value", typ: i(0) },
+    ], "any"),
+    "EnumValues": o([
+        { json: "label", js: "label", typ: "" },
+    ], "any"),
+    "FormatException": o([
+        { json: "count", js: "count", typ: i(0) },
+    ], "any"),
+    "RegExp": o([
+        { json: "active", js: "active", typ: true },
+    ], "any"),
+    "Status": [
+        "ready",
+        "done",
+    ],
+};
+
+module.exports = {
+    "topLevelToJson": topLevelToJson,
+    "toTopLevel": toTopLevel,
+};
diff --git a/head/schema-javascript-prop-types/test/inputs/schema/dart-runtime-type-names.schema/default/toplevel.js b/head/schema-javascript-prop-types/test/inputs/schema/dart-runtime-type-names.schema/default/toplevel.js
new file mode 100644
index 0000000..23751d4
--- /dev/null
+++ b/head/schema-javascript-prop-types/test/inputs/schema/dart-runtime-type-names.schema/default/toplevel.js
@@ -0,0 +1,44 @@
+// Example usage:
+//
+// import { MyShape } from ./myShape.js;
+//
+// class MyComponent extends React.Component {
+//   //
+// }
+//
+// MyComponent.propTypes = {
+//   input: MyShape
+// };
+
+import PropTypes from "prop-types";
+const Integer = (props, name) => props[name] == null || Number.isInteger(props[name]) ? null : new Error("Expected integer");
+
+let _TopLevel;
+let _DateTime;
+let _EnumValues;
+let _FormatException;
+let _RegExp;
+const _Status = PropTypes.oneOf(['ready', 'done']);
+_DateTime = PropTypes.shape({
+    "value": PropTypes.oneOfType([Integer]).isRequired,
+});
+_EnumValues = PropTypes.shape({
+    "label": PropTypes.oneOfType([PropTypes.string]).isRequired,
+});
+_FormatException = PropTypes.shape({
+    "count": PropTypes.oneOfType([Integer]).isRequired,
+});
+_RegExp = PropTypes.shape({
+    "active": PropTypes.oneOfType([PropTypes.bool]).isRequired,
+});
+_TopLevel = PropTypes.shape({
+    "code": PropTypes.oneOfType([(props, name) => { const value = props[name]; return value == null || (typeof value === 'string' && value.length >= 1 && new RegExp("^[a-z]+$").test(value)) ? null : new Error("Expected bounded string"); }]).isRequired,
+    "dateTime": _DateTime,
+    "enumValues": _EnumValues,
+    "formatException": _FormatException,
+    "regExp": _RegExp,
+    "status": _Status,
+    "timestamp": PropTypes.oneOfType([(props, name) => props[name] == null || !Number.isNaN(Date.parse(props[name])) ? null : new Error("Expected date-time")]).isRequired,
+});
+
+export const TopLevel = _TopLevel;
diff --git a/head/schema-kotlin/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.kt b/head/schema-kotlin/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.kt
new file mode 100644
index 0000000..658cc3d
--- /dev/null
+++ b/head/schema-kotlin/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.kt
@@ -0,0 +1,72 @@
+// To parse the JSON, install Klaxon and do:
+//
+//   val topLevel = TopLevel.fromJson(jsonString)
+
+package quicktype
+
+import java.time.OffsetDateTime
+
+import com.beust.klaxon.*
+
+private fun <T> Klaxon.convert(k: kotlin.reflect.KClass<*>, fromJson: (JsonValue) -> T, toJson: (T) -> String, isUnion: Boolean = false) =
+    this.converter(object: Converter {
+        @Suppress("UNCHECKED_CAST")
+        override fun toJson(value: Any)        = toJson(value as T)
+        override fun fromJson(jv: JsonValue)   = fromJson(jv) as Any
+        override fun canConvert(cls: Class<*>) = cls == k.java || (isUnion && cls.superclass == k.java)
+    })
+
+private val klaxon = Klaxon()
+    .convert(OffsetDateTime::class, { OffsetDateTime.parse(it.string!!) }, { "\"${java.time.format.DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(it)}\"" })
+    .convert(Status::class,         { Status.fromValue(it.string!!) },     { "\"${it.value}\"" })
+
+data class TopLevel (
+    val code: String,
+    val dateTime: DateTime,
+    val enumValues: EnumValues,
+    val formatException: FormatException,
+    val regExp: RegExp,
+    val status: Status,
+    val timestamp: OffsetDateTime
+) {
+    init {
+        require(code.length >= 1)
+    }
+    init {
+        require(Regex("^[a-z]+\$").containsMatchIn(code))
+    }
+    public fun toJson() = klaxon.toJsonString(this)
+
+    companion object {
+        public fun fromJson(json: String) = klaxon.parse<TopLevel>(json)
+    }
+}
+
+data class DateTime (
+    val value: Long
+)
+
+data class EnumValues (
+    val label: String
+)
+
+data class FormatException (
+    val count: Long
+)
+
+data class RegExp (
+    val active: Boolean
+)
+
+enum class Status(val value: String) {
+    Ready("ready"),
+    Done("done");
+
+    companion object {
+        public fun fromValue(value: String): Status = when (value) {
+            "ready" -> Ready
+            "done"  -> Done
+            else    -> throw IllegalArgumentException()
+        }
+    }
+}
diff --git a/head/schema-kotlin-jackson/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.kt b/head/schema-kotlin-jackson/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.kt
new file mode 100644
index 0000000..6c9cb40
--- /dev/null
+++ b/head/schema-kotlin-jackson/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.kt
@@ -0,0 +1,101 @@
+// To parse the JSON, install jackson-module-kotlin and do:
+//
+//   val topLevel = TopLevel.fromJson(jsonString)
+
+package quicktype
+
+import java.time.OffsetDateTime
+
+import com.fasterxml.jackson.annotation.*
+import com.fasterxml.jackson.core.*
+import com.fasterxml.jackson.databind.*
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer
+import com.fasterxml.jackson.databind.module.SimpleModule
+import com.fasterxml.jackson.databind.node.*
+import com.fasterxml.jackson.databind.ser.std.StdSerializer
+import com.fasterxml.jackson.module.kotlin.*
+
+
+@Suppress("UNCHECKED_CAST")
+private fun <T> ObjectMapper.convert(k: kotlin.reflect.KClass<*>, fromJson: (JsonNode) -> T, toJson: (T) -> String, isUnion: Boolean = false) = registerModule(SimpleModule().apply {
+    addSerializer(k.java as Class<T>, object : StdSerializer<T>(k.java as Class<T>) {
+            override fun serialize(value: T, gen: JsonGenerator, provider: SerializerProvider) = gen.writeRawValue(toJson(value))
+    })
+    addDeserializer(k.java as Class<T>, object : StdDeserializer<T>(k.java as Class<T>) {
+            override fun deserialize(p: JsonParser, ctxt: DeserializationContext) = fromJson(p.readValueAsTree())
+    })
+})
+
+val mapper = jacksonObjectMapper().apply {
+    propertyNamingStrategy = object : PropertyNamingStrategy.PropertyNamingStrategyBase() { override fun translate(name: String) = if (name == "empty") "" else name }
+    setSerializationInclusion(JsonInclude.Include.NON_NULL)
+    disable(DeserializationFeature.ACCEPT_FLOAT_AS_INT)
+    convert(OffsetDateTime::class, { OffsetDateTime.parse(it.asText()) }, { "\"${java.time.format.DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(it)}\"" })
+    convert(Status::class,         { Status.fromValue(it.asText()) },     { "\"${it.value}\"" })
+}
+
+data class TopLevel (
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val code: String,
+
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val dateTime: DateTime,
+
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val enumValues: EnumValues,
+
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val formatException: FormatException,
+
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val regExp: RegExp,
+
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val status: Status,
+
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val timestamp: OffsetDateTime
+) {
+    init {
+        require(code.length >= 1)
+        require(Regex("^[a-z]+\$").containsMatchIn(code))
+    }
+    fun toJson() = mapper.writeValueAsString(this)
+
+    companion object {
+        fun fromJson(json: String) = mapper.readValue<TopLevel>(json)
+    }
+}
+
+data class DateTime (
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val value: Long
+)
+
+data class EnumValues (
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val label: String
+)
+
+data class FormatException (
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val count: Long
+)
+
+data class RegExp (
+    @get:JsonProperty(required=true)@field:JsonProperty(required=true)
+    val active: Boolean
+)
+
+enum class Status(val value: String) {
+    Ready("ready"),
+    Done("done");
+
+    companion object {
+        fun fromValue(value: String): Status = when (value) {
+            "ready" -> Ready
+            "done"  -> Done
+            else    -> throw IllegalArgumentException()
+        }
+    }
+}
diff --git a/head/schema-kotlinx/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.kt b/head/schema-kotlinx/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.kt
new file mode 100644
index 0000000..35517d1
--- /dev/null
+++ b/head/schema-kotlinx/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.kt
@@ -0,0 +1,60 @@
+// To parse the JSON, install kotlin's serialization plugin and do:
+//
+// val json     = Json { allowStructuredMapKeys = true }
+// val topLevel = json.parse(TopLevel.serializer(), jsonString)
+
+@file:UseSerializers(OffsetDateTimeSerializer::class)
+
+package quicktype
+
+import java.time.OffsetDateTime
+
+import kotlinx.serialization.*
+import kotlinx.serialization.json.*
+import kotlinx.serialization.descriptors.*
+import kotlinx.serialization.encoding.*
+
+@Serializable
+data class TopLevel (
+    val code: String,
+    val dateTime: DateTime,
+    val enumValues: EnumValues,
+    val formatException: FormatException,
+    val regExp: RegExp,
+    val status: Status,
+    val timestamp: OffsetDateTime
+)
+
+@Serializable
+data class DateTime (
+    val value: Long
+)
+
+@Serializable
+data class EnumValues (
+    val label: String
+)
+
+@Serializable
+data class FormatException (
+    val count: Long
+)
+
+@Serializable
+data class RegExp (
+    val active: Boolean
+)
+
+@Serializable
+enum class Status(val value: String) {
+    @SerialName("ready") Ready("ready"),
+    @SerialName("done") Done("done");
+}
+
+object OffsetDateTimeSerializer : KSerializer<OffsetDateTime> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("OffsetDateTime", PrimitiveKind.STRING)
+    override fun deserialize(decoder: Decoder): OffsetDateTime = OffsetDateTime.parse(decoder.decodeString())
+    override fun serialize(encoder: Encoder, value: OffsetDateTime) {
+        encoder.encodeString(java.time.format.DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(value))
+    }
+}
diff --git a/head/schema-objective-c/test/inputs/schema/dart-runtime-type-names.schema/default/QTTopLevel.h b/head/schema-objective-c/test/inputs/schema/dart-runtime-type-names.schema/default/QTTopLevel.h
new file mode 100644
index 0000000..33fa558
--- /dev/null
+++ b/head/schema-objective-c/test/inputs/schema/dart-runtime-type-names.schema/default/QTTopLevel.h
@@ -0,0 +1,66 @@
+// To parse this JSON:
+//
+//   NSError *error;
+//   QTTopLevel *topLevel = [QTTopLevel fromJSON:json encoding:NSUTF8Encoding error:&error];
+
+#import <Foundation/Foundation.h>
+
+@class QTTopLevel;
+@class QTDateTime;
+@class QTEnumValues;
+@class QTFormatException;
+@class QTRegExp;
+@class QTStatus;
+
+NS_ASSUME_NONNULL_BEGIN
+
+#pragma mark - Boxed enums
+
+@interface QTStatus : NSObject
+@property (nonatomic, readonly, copy) NSString *value;
++ (instancetype _Nullable)withValue:(NSString *)value;
++ (QTStatus *)ready;
++ (QTStatus *)done;
+@end
+
+#pragma mark - Top-level marshaling functions
+
+QTTopLevel *_Nullable QTTopLevelFromData(NSData *data, NSError **error);
+QTTopLevel *_Nullable QTTopLevelFromJSON(NSString *json, NSStringEncoding encoding, NSError **error);
+NSData     *_Nullable QTTopLevelToData(QTTopLevel *topLevel, NSError **error);
+NSString   *_Nullable QTTopLevelToJSON(QTTopLevel *topLevel, NSStringEncoding encoding, NSError **error);
+
+#pragma mark - Object interfaces
+
+@interface QTTopLevel : NSObject
+@property (nonatomic, copy)   NSString *code;
+@property (nonatomic, strong) QTDateTime *dateTime;
+@property (nonatomic, strong) QTEnumValues *enumValues;
+@property (nonatomic, strong) QTFormatException *formatException;
+@property (nonatomic, strong) QTRegExp *regExp;
+@property (nonatomic, assign) QTStatus *status;
+@property (nonatomic, copy)   NSString *timestamp;
+
++ (_Nullable instancetype)fromJSON:(NSString *)json encoding:(NSStringEncoding)encoding error:(NSError *_Nullable *)error;
++ (_Nullable instancetype)fromData:(NSData *)data error:(NSError *_Nullable *)error;
+- (NSString *_Nullable)toJSON:(NSStringEncoding)encoding error:(NSError *_Nullable *)error;
+- (NSData *_Nullable)toData:(NSError *_Nullable *)error;
+@end
+
+@interface QTDateTime : NSObject
+@property (nonatomic, assign) NSInteger value;
+@end
+
+@interface QTEnumValues : NSObject
+@property (nonatomic, copy) NSString *label;
+@end
+
+@interface QTFormatException : NSObject
+@property (nonatomic, assign) NSInteger count;
+@end
+
+@interface QTRegExp : NSObject
+@property (nonatomic, assign) BOOL isActive;
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/head/schema-objective-c/test/inputs/schema/dart-runtime-type-names.schema/default/QTTopLevel.m b/head/schema-objective-c/test/inputs/schema/dart-runtime-type-names.schema/default/QTTopLevel.m
new file mode 100644
index 0000000..5c76b76
--- /dev/null
+++ b/head/schema-objective-c/test/inputs/schema/dart-runtime-type-names.schema/default/QTTopLevel.m
@@ -0,0 +1,374 @@
+#import "QTTopLevel.h"
+
+#define λ(decl, expr) (^(decl) { return (expr); })
+
+static id NSNullify(id _Nullable x) {
+    return (x == nil || x == NSNull.null) ? NSNull.null : x;
+}
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface QTTopLevel (JSONConversion)
++ (instancetype)fromJSONDictionary:(NSDictionary *)dict;
+- (NSDictionary *)JSONDictionary;
+@end
+
+@interface QTDateTime (JSONConversion)
++ (instancetype)fromJSONDictionary:(NSDictionary *)dict;
+- (NSDictionary *)JSONDictionary;
+@end
+
+@interface QTEnumValues (JSONConversion)
++ (instancetype)fromJSONDictionary:(NSDictionary *)dict;
+- (NSDictionary *)JSONDictionary;
+@end
+
+@interface QTFormatException (JSONConversion)
++ (instancetype)fromJSONDictionary:(NSDictionary *)dict;
+- (NSDictionary *)JSONDictionary;
+@end
+
+@interface QTRegExp (JSONConversion)
++ (instancetype)fromJSONDictionary:(NSDictionary *)dict;
+- (NSDictionary *)JSONDictionary;
+@end
+
+@implementation QTStatus
++ (NSDictionary<NSString *, QTStatus *> *)values
+{
+    static NSDictionary<NSString *, QTStatus *> *values;
+    return values = values ? values : @{
+        @"ready": [[QTStatus alloc] initWithValue:@"ready"],
+        @"done": [[QTStatus alloc] initWithValue:@"done"],
+    };
+}
+
++ (QTStatus *)ready { return QTStatus.values[@"ready"]; }
++ (QTStatus *)done { return QTStatus.values[@"done"]; }
+
++ (instancetype _Nullable)withValue:(NSString *)value
+{
+    return QTStatus.values[value];
+}
+
+- (instancetype)initWithValue:(NSString *)value
+{
+    if (self = [super init]) _value = value;
+    return self;
+}
+
+- (NSUInteger)hash { return _value.hash; }
+@end
+
+#pragma mark - JSON serialization
+
+QTTopLevel *_Nullable QTTopLevelFromData(NSData *data, NSError **error)
+{
+    @try {
+        id json = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:error];
+        return *error ? nil : [QTTopLevel fromJSONDictionary:json];
+    } @catch (NSException *exception) {
+        *error = [NSError errorWithDomain:@"JSONSerialization" code:-1 userInfo:@{ @"exception": exception }];
+        return nil;
+    }
+}
+
+QTTopLevel *_Nullable QTTopLevelFromJSON(NSString *json, NSStringEncoding encoding, NSError **error)
+{
+    return QTTopLevelFromData([json dataUsingEncoding:encoding], error);
+}
+
+NSData *_Nullable QTTopLevelToData(QTTopLevel *topLevel, NSError **error)
+{
+    @try {
+        id json = [topLevel JSONDictionary];
+        NSData *data = [NSJSONSerialization dataWithJSONObject:json options:NSJSONWritingFragmentsAllowed error:error];
+        return *error ? nil : data;
+    } @catch (NSException *exception) {
+        *error = [NSError errorWithDomain:@"JSONSerialization" code:-1 userInfo:@{ @"exception": exception }];
+        return nil;
+    }
+}
+
+NSString *_Nullable QTTopLevelToJSON(QTTopLevel *topLevel, NSStringEncoding encoding, NSError **error)
+{
+    NSData *data = QTTopLevelToData(topLevel, error);
+    return data ? [[NSString alloc] initWithData:data encoding:encoding] : nil;
+}
+
+@implementation QTTopLevel
++ (NSDictionary<NSString *, NSString *> *)properties
+{
+    static NSDictionary<NSString *, NSString *> *properties;
+    return properties = properties ? properties : @{
+        @"code": @"code",
+        @"dateTime": @"dateTime",
+        @"enumValues": @"enumValues",
+        @"formatException": @"formatException",
+        @"regExp": @"regExp",
+        @"status": @"status",
+        @"timestamp": @"timestamp",
+    };
+}
+
++ (_Nullable instancetype)fromData:(NSData *)data error:(NSError *_Nullable *)error
+{
+    return QTTopLevelFromData(data, error);
+}
+
++ (_Nullable instancetype)fromJSON:(NSString *)json encoding:(NSStringEncoding)encoding error:(NSError *_Nullable *)error
+{
+    return QTTopLevelFromJSON(json, encoding, error);
+}
+
++ (instancetype)fromJSONDictionary:(NSDictionary *)dict
+{
+    return [dict isKindOfClass:NSDictionary.class] ? [[QTTopLevel alloc] initWithJSONDictionary:dict] : nil;
+}
+
+- (instancetype)initWithJSONDictionary:(NSDictionary *)dict
+{
+    if (self = [super init]) {
+        if (dict[@"code"] && [dict[@"code"] rangeOfString:@"^[a-z]+$" options:NSRegularExpressionSearch].location == NSNotFound) return nil;
+        if (dict[@"code"] && [dict[@"code"] length] < 1) return nil;
+        if (![dict[@"code"] isKindOfClass:NSString.class]) return nil;
+        if (![dict[@"dateTime"] isKindOfClass:NSDictionary.class]) return nil;
+        if (![dict[@"enumValues"] isKindOfClass:NSDictionary.class]) return nil;
+        if (![dict[@"formatException"] isKindOfClass:NSDictionary.class]) return nil;
+        if (![dict[@"regExp"] isKindOfClass:NSDictionary.class]) return nil;
+        if (![dict[@"status"] isKindOfClass:NSString.class]) return nil;
+        if (dict[@"timestamp"] && [dict[@"timestamp"] rangeOfString:@"^[0-9]{4}-[0-9]{2}-[0-9]{2}T" options:NSRegularExpressionSearch].location == NSNotFound) return nil;
+        if (![dict[@"timestamp"] isKindOfClass:NSString.class]) return nil;
+        [self setValuesForKeysWithDictionary:dict];
+        _dateTime = [QTDateTime fromJSONDictionary:(id)_dateTime];
+        if (!_dateTime && dict[@"dateTime"] && ![dict[@"dateTime"] isKindOfClass:NSNull.class]) return nil;
+        _enumValues = [QTEnumValues fromJSONDictionary:(id)_enumValues];
+        if (!_enumValues && dict[@"enumValues"] && ![dict[@"enumValues"] isKindOfClass:NSNull.class]) return nil;
+        _formatException = [QTFormatException fromJSONDictionary:(id)_formatException];
+        if (!_formatException && dict[@"formatException"] && ![dict[@"formatException"] isKindOfClass:NSNull.class]) return nil;
+        _regExp = [QTRegExp fromJSONDictionary:(id)_regExp];
+        if (!_regExp && dict[@"regExp"] && ![dict[@"regExp"] isKindOfClass:NSNull.class]) return nil;
+        _status = [QTStatus withValue:(id)_status];
+    }
+    return self;
+}
+
+- (void)setValue:(nullable id)value forKey:(NSString *)key
+{
+    id resolved = QTTopLevel.properties[key];
+    if (resolved) [super setValue:value forKey:resolved];
+}
+
+- (void)setNilValueForKey:(NSString *)key
+{
+    id resolved = QTTopLevel.properties[key];
+    if (resolved) [super setValue:@(0) forKey:resolved];
+}
+
+- (NSDictionary *)JSONDictionary
+{
+    id dict = [[self dictionaryWithValuesForKeys:QTTopLevel.properties.allValues] mutableCopy];
+
+    [dict addEntriesFromDictionary:@{
+        @"dateTime": [_dateTime JSONDictionary],
+        @"enumValues": [_enumValues JSONDictionary],
+        @"formatException": [_formatException JSONDictionary],
+        @"regExp": [_regExp JSONDictionary],
+        @"status": [_status value],
+    }];
+
+    return dict;
+}
+
+- (NSData *_Nullable)toData:(NSError *_Nullable *)error
+{
+    return QTTopLevelToData(self, error);
+}
+
+- (NSString *_Nullable)toJSON:(NSStringEncoding)encoding error:(NSError *_Nullable *)error
+{
+    return QTTopLevelToJSON(self, encoding, error);
+}
+@end
+
+@implementation QTDateTime
++ (NSDictionary<NSString *, NSString *> *)properties
+{
+    static NSDictionary<NSString *, NSString *> *properties;
+    return properties = properties ? properties : @{
+        @"value": @"value",
+    };
+}
+
++ (instancetype)fromJSONDictionary:(NSDictionary *)dict
+{
+    return [dict isKindOfClass:NSDictionary.class] ? [[QTDateTime alloc] initWithJSONDictionary:dict] : nil;
+}
+
+- (instancetype)initWithJSONDictionary:(NSDictionary *)dict
+{
+    if (self = [super init]) {
+        if (![dict[@"value"] isKindOfClass:NSNumber.class]) return nil;
+        if ([dict[@"value"] doubleValue] != [dict[@"value"] longLongValue]) return nil;
+        [self setValuesForKeysWithDictionary:dict];
+    }
+    return self;
+}
+
+- (void)setValue:(nullable id)value forKey:(NSString *)key
+{
+    id resolved = QTDateTime.properties[key];
+    if (resolved) [super setValue:value forKey:resolved];
+}
+
+- (void)setNilValueForKey:(NSString *)key
+{
+    id resolved = QTDateTime.properties[key];
+    if (resolved) [super setValue:@(0) forKey:resolved];
+}
+
+- (NSDictionary *)JSONDictionary
+{
+    return [self dictionaryWithValuesForKeys:QTDateTime.properties.allValues];
+}
+@end
+
+@implementation QTEnumValues
++ (NSDictionary<NSString *, NSString *> *)properties
+{
+    static NSDictionary<NSString *, NSString *> *properties;
+    return properties = properties ? properties : @{
+        @"label": @"label",
+    };
+}
+
++ (instancetype)fromJSONDictionary:(NSDictionary *)dict
+{
+    return [dict isKindOfClass:NSDictionary.class] ? [[QTEnumValues alloc] initWithJSONDictionary:dict] : nil;
+}
+
+- (instancetype)initWithJSONDictionary:(NSDictionary *)dict
+{
+    if (self = [super init]) {
+        if (![dict[@"label"] isKindOfClass:NSString.class]) return nil;
+        [self setValuesForKeysWithDictionary:dict];
+    }
+    return self;
+}
+
+- (void)setValue:(nullable id)value forKey:(NSString *)key
+{
+    id resolved = QTEnumValues.properties[key];
+    if (resolved) [super setValue:value forKey:resolved];
+}
+
+- (void)setNilValueForKey:(NSString *)key
+{
+    id resolved = QTEnumValues.properties[key];
+    if (resolved) [super setValue:@(0) forKey:resolved];
+}
+
+- (NSDictionary *)JSONDictionary
+{
+    return [self dictionaryWithValuesForKeys:QTEnumValues.properties.allValues];
+}
+@end
+
+@implementation QTFormatException
++ (NSDictionary<NSString *, NSString *> *)properties
+{
+    static NSDictionary<NSString *, NSString *> *properties;
+    return properties = properties ? properties : @{
+        @"count": @"count",
+    };
+}
+
++ (instancetype)fromJSONDictionary:(NSDictionary *)dict
+{
+    return [dict isKindOfClass:NSDictionary.class] ? [[QTFormatException alloc] initWithJSONDictionary:dict] : nil;
+}
+
+- (instancetype)initWithJSONDictionary:(NSDictionary *)dict
+{
+    if (self = [super init]) {
+        if (![dict[@"count"] isKindOfClass:NSNumber.class]) return nil;
+        if ([dict[@"count"] doubleValue] != [dict[@"count"] longLongValue]) return nil;
+        [self setValuesForKeysWithDictionary:dict];
+    }
+    return self;
+}
+
+- (void)setValue:(nullable id)value forKey:(NSString *)key
+{
+    id resolved = QTFormatException.properties[key];
+    if (resolved) [super setValue:value forKey:resolved];
+}
+
+- (void)setNilValueForKey:(NSString *)key
+{
+    id resolved = QTFormatException.properties[key];
+    if (resolved) [super setValue:@(0) forKey:resolved];
+}
+
+- (NSDictionary *)JSONDictionary
+{
+    return [self dictionaryWithValuesForKeys:QTFormatException.properties.allValues];
+}
+@end
+
+@implementation QTRegExp
++ (NSDictionary<NSString *, NSString *> *)properties
+{
+    static NSDictionary<NSString *, NSString *> *properties;
+    return properties = properties ? properties : @{
+        @"active": @"isActive",
+    };
+}
+
++ (instancetype)fromJSONDictionary:(NSDictionary *)dict
+{
+    return [dict isKindOfClass:NSDictionary.class] ? [[QTRegExp alloc] initWithJSONDictionary:dict] : nil;
+}
+
+- (instancetype)initWithJSONDictionary:(NSDictionary *)dict
+{
+    if (self = [super init]) {
+        if (![dict[@"active"] isKindOfClass:NSNumber.class]) return nil;
+        [self setValuesForKeysWithDictionary:dict];
+    }
+    return self;
+}
+
+- (void)setValue:(nullable id)value forKey:(NSString *)key
+{
+    id resolved = QTRegExp.properties[key];
+    if (resolved) [super setValue:value forKey:resolved];
+}
+
+- (void)setNilValueForKey:(NSString *)key
+{
+    id resolved = QTRegExp.properties[key];
+    if (resolved) [super setValue:@(0) forKey:resolved];
+}
+
+- (NSDictionary *)JSONDictionary
+{
+    id dict = [[self dictionaryWithValuesForKeys:QTRegExp.properties.allValues] mutableCopy];
+
+    for (id jsonName in QTRegExp.properties) {
+        id propertyName = QTRegExp.properties[jsonName];
+        if (![jsonName isEqualToString:propertyName]) {
+            dict[jsonName] = dict[propertyName];
+            [dict removeObjectForKey:propertyName];
+        }
+    }
+
+    [dict addEntriesFromDictionary:@{
+        @"active": _isActive ? @YES : @NO,
+    }];
+
+    return dict;
+}
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/head/schema-php/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.php b/head/schema-php/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.php
new file mode 100644
index 0000000..09e5971
--- /dev/null
+++ b/head/schema-php/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.php
@@ -0,0 +1,916 @@
+<?php
+declare(strict_types=1);
+
+// This is an autogenerated file:TopLevel
+
+class TopLevel {
+    private string $code; // json:code Required
+    private DateTimeClass $dateTime; // json:dateTime Required
+    private EnumValues $enumValues; // json:enumValues Required
+    private FormatException $formatException; // json:formatException Required
+    private RegExp $regExp; // json:regExp Required
+    private Status $status; // json:status Required
+    private DateTime $timestamp; // json:timestamp Required
+
+    /**
+     * @param string $code
+     * @param DateTimeClass $dateTime
+     * @param EnumValues $enumValues
+     * @param FormatException $formatException
+     * @param RegExp $regExp
+     * @param Status $status
+     * @param DateTime $timestamp
+     */
+    public function __construct(string $code, DateTimeClass $dateTime, EnumValues $enumValues, FormatException $formatException, RegExp $regExp, Status $status, DateTime $timestamp) {
+        $this->code = $code;
+        $this->dateTime = $dateTime;
+        $this->enumValues = $enumValues;
+        $this->formatException = $formatException;
+        $this->regExp = $regExp;
+        $this->status = $status;
+        $this->timestamp = $timestamp;
+    }
+
+    /**
+     * @param string $value
+     * @throws Exception
+     * @return string
+     */
+    public static function fromCode(string $value): string {
+        return $value; /*string*/
+    }
+
+    /**
+     * @throws Exception
+     * @return string
+     */
+    public function toCode(): string {
+        if (TopLevel::validateCode($this->code))  {
+            return $this->code; /*string*/
+        }
+        throw new Exception('never get to this TopLevel::code');
+    }
+
+    /**
+     * @param string
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateCode(string $value): bool {
+        if (preg_match_all('/./us', $value) < 1) {
+            throw new Exception("Attribute Error");
+        }
+        if (preg_match('~^[a-z]+$~u', $value) !== 1) {
+            throw new Exception("Attribute Error");
+        }
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return string
+     */
+    public function getCode(): string {
+        if (TopLevel::validateCode($this->code))  {
+            return $this->code;
+        }
+        throw new Exception('never get to getCode TopLevel::code');
+    }
+
+    /**
+     * @return string
+     */
+    public static function sampleCode(): string {
+        return 'TopLevel::code::31'; /*31:code*/
+    }
+
+    /**
+     * @param stdClass $value
+     * @throws Exception
+     * @return DateTimeClass
+     */
+    public static function fromDateTime(stdClass $value): DateTimeClass {
+        return DateTimeClass::from($value); /*class*/
+    }
+
+    /**
+     * @throws Exception
+     * @return stdClass
+     */
+    public function toDateTime(): stdClass {
+        if (TopLevel::validateDateTime($this->dateTime))  {
+            return $this->dateTime->to(); /*class*/
+        }
+        throw new Exception('never get to this TopLevel::dateTime');
+    }
+
+    /**
+     * @param DateTimeClass
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateDateTime(DateTimeClass $value): bool {
+        $value->validate();
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return DateTimeClass
+     */
+    public function getDateTime(): DateTimeClass {
+        if (TopLevel::validateDateTime($this->dateTime))  {
+            return $this->dateTime;
+        }
+        throw new Exception('never get to getDateTime TopLevel::dateTime');
+    }
+
+    /**
+     * @return DateTimeClass
+     */
+    public static function sampleDateTime(): DateTimeClass {
+        return DateTimeClass::sample(); /*32:dateTime*/
+    }
+
+    /**
+     * @param stdClass $value
+     * @throws Exception
+     * @return EnumValues
+     */
+    public static function fromEnumValues(stdClass $value): EnumValues {
+        return EnumValues::from($value); /*class*/
+    }
+
+    /**
+     * @throws Exception
+     * @return stdClass
+     */
+    public function toEnumValues(): stdClass {
+        if (TopLevel::validateEnumValues($this->enumValues))  {
+            return $this->enumValues->to(); /*class*/
+        }
+        throw new Exception('never get to this TopLevel::enumValues');
+    }
+
+    /**
+     * @param EnumValues
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateEnumValues(EnumValues $value): bool {
+        $value->validate();
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return EnumValues
+     */
+    public function getEnumValues(): EnumValues {
+        if (TopLevel::validateEnumValues($this->enumValues))  {
+            return $this->enumValues;
+        }
+        throw new Exception('never get to getEnumValues TopLevel::enumValues');
+    }
+
+    /**
+     * @return EnumValues
+     */
+    public static function sampleEnumValues(): EnumValues {
+        return EnumValues::sample(); /*33:enumValues*/
+    }
+
+    /**
+     * @param stdClass $value
+     * @throws Exception
+     * @return FormatException
+     */
+    public static function fromFormatException(stdClass $value): FormatException {
+        return FormatException::from($value); /*class*/
+    }
+
+    /**
+     * @throws Exception
+     * @return stdClass
+     */
+    public function toFormatException(): stdClass {
+        if (TopLevel::validateFormatException($this->formatException))  {
+            return $this->formatException->to(); /*class*/
+        }
+        throw new Exception('never get to this TopLevel::formatException');
+    }
+
+    /**
+     * @param FormatException
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateFormatException(FormatException $value): bool {
+        $value->validate();
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return FormatException
+     */
+    public function getFormatException(): FormatException {
+        if (TopLevel::validateFormatException($this->formatException))  {
+            return $this->formatException;
+        }
+        throw new Exception('never get to getFormatException TopLevel::formatException');
+    }
+
+    /**
+     * @return FormatException
+     */
+    public static function sampleFormatException(): FormatException {
+        return FormatException::sample(); /*34:formatException*/
+    }
+
+    /**
+     * @param stdClass $value
+     * @throws Exception
+     * @return RegExp
+     */
+    public static function fromRegExp(stdClass $value): RegExp {
+        return RegExp::from($value); /*class*/
+    }
+
+    /**
+     * @throws Exception
+     * @return stdClass
+     */
+    public function toRegExp(): stdClass {
+        if (TopLevel::validateRegExp($this->regExp))  {
+            return $this->regExp->to(); /*class*/
+        }
+        throw new Exception('never get to this TopLevel::regExp');
+    }
+
+    /**
+     * @param RegExp
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateRegExp(RegExp $value): bool {
+        $value->validate();
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return RegExp
+     */
+    public function getRegExp(): RegExp {
+        if (TopLevel::validateRegExp($this->regExp))  {
+            return $this->regExp;
+        }
+        throw new Exception('never get to getRegExp TopLevel::regExp');
+    }
+
+    /**
+     * @return RegExp
+     */
+    public static function sampleRegExp(): RegExp {
+        return RegExp::sample(); /*35:regExp*/
+    }
+
+    /**
+     * @param string $value
+     * @throws Exception
+     * @return Status
+     */
+    public static function fromStatus(string $value): Status {
+        return Status::from($value); /*enum*/
+    }
+
+    /**
+     * @throws Exception
+     * @return string
+     */
+    public function toStatus(): string {
+        if (TopLevel::validateStatus($this->status))  {
+            return Status::to($this->status); /*enum*/
+        }
+        throw new Exception('never get to this TopLevel::status');
+    }
+
+    /**
+     * @param Status
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateStatus(Status $value): bool {
+        Status::to($value);
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return Status
+     */
+    public function getStatus(): Status {
+        if (TopLevel::validateStatus($this->status))  {
+            return $this->status;
+        }
+        throw new Exception('never get to getStatus TopLevel::status');
+    }
+
+    /**
+     * @return Status
+     */
+    public static function sampleStatus(): Status {
+        return Status::sample(); /*enum*/
+    }
+
+    /**
+     * @param string $value
+     * @throws Exception
+     * @return DateTime
+     */
+    public static function fromTimestamp(string $value): DateTime {
+        $tmp = new DateTime($value);
+        if (!is_a($tmp, 'DateTime')) {
+            throw new Exception('Attribute Error:TopLevel::');
+        }
+        return $tmp;
+    }
+
+    /**
+     * @throws Exception
+     * @return string
+     */
+    public function toTimestamp(): string {
+        if (TopLevel::validateTimestamp($this->timestamp))  {
+            return $this->timestamp->format("Y-m-d\\TH:i:s.uP");
+        }
+        throw new Exception('never get to this TopLevel::timestamp');
+    }
+
+    /**
+     * @param DateTime
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateTimestamp(DateTime $value): bool {
+        if (!is_a($value, 'DateTime')) {
+            throw new Exception('Attribute Error:TopLevel::timestamp');
+        }
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return DateTime
+     */
+    public function getTimestamp(): DateTime {
+        if (TopLevel::validateTimestamp($this->timestamp))  {
+            return $this->timestamp;
+        }
+        throw new Exception('never get to getTimestamp TopLevel::timestamp');
+    }
+
+    /**
+     * @return DateTime
+     */
+    public static function sampleTimestamp(): DateTime {
+        return DateTime::createFromFormat(DateTimeInterface::ISO8601, '2020-12-70T12:70:70+00:00');
+    }
+
+    /**
+     * @throws Exception
+     * @return bool
+     */
+    public function validate(): bool {
+        return TopLevel::validateCode($this->code)
+        || TopLevel::validateDateTime($this->dateTime)
+        || TopLevel::validateEnumValues($this->enumValues)
+        || TopLevel::validateFormatException($this->formatException)
+        || TopLevel::validateRegExp($this->regExp)
+        || TopLevel::validateStatus($this->status)
+        || TopLevel::validateTimestamp($this->timestamp);
+    }
+
+    /**
+     * @return stdClass
+     * @throws Exception
+     */
+    public function to(): stdClass  {
+        $out = new stdClass();
+        $out->{'code'} = $this->toCode();
+        $out->{'dateTime'} = $this->toDateTime();
+        $out->{'enumValues'} = $this->toEnumValues();
+        $out->{'formatException'} = $this->toFormatException();
+        $out->{'regExp'} = $this->toRegExp();
+        $out->{'status'} = $this->toStatus();
+        $out->{'timestamp'} = $this->toTimestamp();
+        return $out;
+    }
+
+    /**
+     * @param stdClass $obj
+     * @return TopLevel
+     * @throws Exception
+     */
+    public static function from(stdClass $obj): TopLevel {
+        if (!property_exists($obj, 'code')) {
+            throw new Exception("Missing required property");
+        }
+        if (!property_exists($obj, 'dateTime')) {
+            throw new Exception("Missing required property");
+        }
+        if (!property_exists($obj, 'enumValues')) {
+            throw new Exception("Missing required property");
+        }
+        if (!property_exists($obj, 'formatException')) {
+            throw new Exception("Missing required property");
+        }
+        if (!property_exists($obj, 'regExp')) {
+            throw new Exception("Missing required property");
+        }
+        if (!property_exists($obj, 'status')) {
+            throw new Exception("Missing required property");
+        }
+        if (!property_exists($obj, 'timestamp')) {
+            throw new Exception("Missing required property");
+        }
+        return new TopLevel(
+         TopLevel::fromCode($obj->{'code'})
+        ,TopLevel::fromDateTime($obj->{'dateTime'})
+        ,TopLevel::fromEnumValues($obj->{'enumValues'})
+        ,TopLevel::fromFormatException($obj->{'formatException'})
+        ,TopLevel::fromRegExp($obj->{'regExp'})
+        ,TopLevel::fromStatus($obj->{'status'})
+        ,TopLevel::fromTimestamp($obj->{'timestamp'})
+        );
+    }
+
+    /**
+     * @return TopLevel
+     */
+    public static function sample(): TopLevel {
+        return new TopLevel(
+         TopLevel::sampleCode()
+        ,TopLevel::sampleDateTime()
+        ,TopLevel::sampleEnumValues()
+        ,TopLevel::sampleFormatException()
+        ,TopLevel::sampleRegExp()
+        ,TopLevel::sampleStatus()
+        ,TopLevel::sampleTimestamp()
+        );
+    }
+}
+
+// This is an autogenerated file:DateTimeClass
+
+class DateTimeClass {
+    private int $value; // json:value Required
+
+    /**
+     * @param int $value
+     */
+    public function __construct(int $value) {
+        $this->value = $value;
+    }
+
+    /**
+     * @param int $value
+     * @throws Exception
+     * @return int
+     */
+    public static function fromValue(int $value): int {
+        return $value; /*int*/
+    }
+
+    /**
+     * @throws Exception
+     * @return int
+     */
+    public function toValue(): int {
+        if (DateTimeClass::validateValue($this->value))  {
+            return $this->value; /*int*/
+        }
+        throw new Exception('never get to this DateTimeClass::value');
+    }
+
+    /**
+     * @param int
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateValue(int $value): bool {
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return int
+     */
+    public function getValue(): int {
+        if (DateTimeClass::validateValue($this->value))  {
+            return $this->value;
+        }
+        throw new Exception('never get to getValue DateTimeClass::value');
+    }
+
+    /**
+     * @return int
+     */
+    public static function sampleValue(): int {
+        return 31; /*31:value*/
+    }
+
+    /**
+     * @throws Exception
+     * @return bool
+     */
+    public function validate(): bool {
+        return DateTimeClass::validateValue($this->value);
+    }
+
+    /**
+     * @return stdClass
+     * @throws Exception
+     */
+    public function to(): stdClass  {
+        $out = new stdClass();
+        $out->{'value'} = $this->toValue();
+        return $out;
+    }
+
+    /**
+     * @param stdClass $obj
+     * @return DateTimeClass
+     * @throws Exception
+     */
+    public static function from(stdClass $obj): DateTimeClass {
+        if (!property_exists($obj, 'value')) {
+            throw new Exception("Missing required property");
+        }
+        return new DateTimeClass(
+         DateTimeClass::fromValue($obj->{'value'})
+        );
+    }
+
+    /**
+     * @return DateTimeClass
+     */
+    public static function sample(): DateTimeClass {
+        return new DateTimeClass(
+         DateTimeClass::sampleValue()
+        );
+    }
+}
+
+// This is an autogenerated file:EnumValues
+
+class EnumValues {
+    private string $label; // json:label Required
+
+    /**
+     * @param string $label
+     */
+    public function __construct(string $label) {
+        $this->label = $label;
+    }
+
+    /**
+     * @param string $value
+     * @throws Exception
+     * @return string
+     */
+    public static function fromLabel(string $value): string {
+        return $value; /*string*/
+    }
+
+    /**
+     * @throws Exception
+     * @return string
+     */
+    public function toLabel(): string {
+        if (EnumValues::validateLabel($this->label))  {
+            return $this->label; /*string*/
+        }
+        throw new Exception('never get to this EnumValues::label');
+    }
+
+    /**
+     * @param string
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateLabel(string $value): bool {
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return string
+     */
+    public function getLabel(): string {
+        if (EnumValues::validateLabel($this->label))  {
+            return $this->label;
+        }
+        throw new Exception('never get to getLabel EnumValues::label');
+    }
+
+    /**
+     * @return string
+     */
+    public static function sampleLabel(): string {
+        return 'EnumValues::label::31'; /*31:label*/
+    }
+
+    /**
+     * @throws Exception
+     * @return bool
+     */
+    public function validate(): bool {
+        return EnumValues::validateLabel($this->label);
+    }
+
+    /**
+     * @return stdClass
+     * @throws Exception
+     */
+    public function to(): stdClass  {
+        $out = new stdClass();
+        $out->{'label'} = $this->toLabel();
+        return $out;
+    }
+
+    /**
+     * @param stdClass $obj
+     * @return EnumValues
+     * @throws Exception
+     */
+    public static function from(stdClass $obj): EnumValues {
+        if (!property_exists($obj, 'label')) {
+            throw new Exception("Missing required property");
+        }
+        return new EnumValues(
+         EnumValues::fromLabel($obj->{'label'})
+        );
+    }
+
+    /**
+     * @return EnumValues
+     */
+    public static function sample(): EnumValues {
+        return new EnumValues(
+         EnumValues::sampleLabel()
+        );
+    }
+}
+
+// This is an autogenerated file:FormatException
+
+class FormatException {
+    private int $count; // json:count Required
+
+    /**
+     * @param int $count
+     */
+    public function __construct(int $count) {
+        $this->count = $count;
+    }
+
+    /**
+     * @param int $value
+     * @throws Exception
+     * @return int
+     */
+    public static function fromCount(int $value): int {
+        return $value; /*int*/
+    }
+
+    /**
+     * @throws Exception
+     * @return int
+     */
+    public function toCount(): int {
+        if (FormatException::validateCount($this->count))  {
+            return $this->count; /*int*/
+        }
+        throw new Exception('never get to this FormatException::count');
+    }
+
+    /**
+     * @param int
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateCount(int $value): bool {
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return int
+     */
+    public function getCount(): int {
+        if (FormatException::validateCount($this->count))  {
+            return $this->count;
+        }
+        throw new Exception('never get to getCount FormatException::count');
+    }
+
+    /**
+     * @return int
+     */
+    public static function sampleCount(): int {
+        return 31; /*31:count*/
+    }
+
+    /**
+     * @throws Exception
+     * @return bool
+     */
+    public function validate(): bool {
+        return FormatException::validateCount($this->count);
+    }
+
+    /**
+     * @return stdClass
+     * @throws Exception
+     */
+    public function to(): stdClass  {
+        $out = new stdClass();
+        $out->{'count'} = $this->toCount();
+        return $out;
+    }
+
+    /**
+     * @param stdClass $obj
+     * @return FormatException
+     * @throws Exception
+     */
+    public static function from(stdClass $obj): FormatException {
+        if (!property_exists($obj, 'count')) {
+            throw new Exception("Missing required property");
+        }
+        return new FormatException(
+         FormatException::fromCount($obj->{'count'})
+        );
+    }
+
+    /**
+     * @return FormatException
+     */
+    public static function sample(): FormatException {
+        return new FormatException(
+         FormatException::sampleCount()
+        );
+    }
+}
+
+// This is an autogenerated file:RegExp
+
+class RegExp {
+    private bool $active; // json:active Required
+
+    /**
+     * @param bool $active
+     */
+    public function __construct(bool $active) {
+        $this->active = $active;
+    }
+
+    /**
+     * @param bool $value
+     * @throws Exception
+     * @return bool
+     */
+    public static function fromActive(bool $value): bool {
+        return $value; /*bool*/
+    }
+
+    /**
+     * @throws Exception
+     * @return bool
+     */
+    public function toActive(): bool {
+        if (RegExp::validateActive($this->active))  {
+            return $this->active; /*bool*/
+        }
+        throw new Exception('never get to this RegExp::active');
+    }
+
+    /**
+     * @param bool
+     * @return bool
+     * @throws Exception
+     */
+    public static function validateActive(bool $value): bool {
+        return true;
+    }
+
+    /**
+     * @throws Exception
+     * @return bool
+     */
+    public function getActive(): bool {
+        if (RegExp::validateActive($this->active))  {
+            return $this->active;
+        }
+        throw new Exception('never get to getActive RegExp::active');
+    }
+
+    /**
+     * @return bool
+     */
+    public static function sampleActive(): bool {
+        return true; /*31:active*/
+    }
+
+    /**
+     * @throws Exception
+     * @return bool
+     */
+    public function validate(): bool {
+        return RegExp::validateActive($this->active);
+    }
+
+    /**
+     * @return stdClass
+     * @throws Exception
+     */
+    public function to(): stdClass  {
+        $out = new stdClass();
+        $out->{'active'} = $this->toActive();
+        return $out;
+    }
+
+    /**
+     * @param stdClass $obj
+     * @return RegExp
+     * @throws Exception
+     */
+    public static function from(stdClass $obj): RegExp {
+        if (!property_exists($obj, 'active')) {
+            throw new Exception("Missing required property");
+        }
+        return new RegExp(
+         RegExp::fromActive($obj->{'active'})
+        );
+    }
+
+    /**
+     * @return RegExp
+     */
+    public static function sample(): RegExp {
+        return new RegExp(
+         RegExp::sampleActive()
+        );
+    }
+}
+
+// This is an autogenerated file:Status
+
+class Status {
+    public static Status $READY;
+    public static Status $DONE;
+    public static function init() {
+        Status::$READY = new Status('ready');
+        Status::$DONE = new Status('done');
+    }
+    private string $enum;
+    public function __construct(string $enum) {
+        $this->enum = $enum;
+    }
+
+    /**
+     * @param Status
+     * @return string
+     * @throws Exception
+     */
+    public static function to(Status $obj): string {
+        switch ($obj->enum) {
+            case Status::$READY->enum: return 'ready';
+            case Status::$DONE->enum: return 'done';
+        }
+        throw new Exception('the give value is not an enum-value.');
+    }
+
+    /**
+     * @param mixed
+     * @return Status
+     * @throws Exception
+     */
+    public static function from($obj): Status {
+        switch ($obj) {
+            case 'ready': return Status::$READY;
+            case 'done': return Status::$DONE;
+        }
+        throw new Exception("Cannot deserialize Status");
+    }
+
+    /**
+     * @return Status
+     */
+    public static function sample(): Status {
+        return Status::$READY;
+    }
+}
+Status::init();
diff --git a/head/schema-pike/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.pmod b/head/schema-pike/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.pmod
new file mode 100644
index 0000000..7c05955
--- /dev/null
+++ b/head/schema-pike/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.pmod
@@ -0,0 +1,145 @@
+// This source has been automatically generated by quicktype.
+// ( https://github.com/quicktype/quicktype )
+//
+// To use this code, simply import it into your project as a Pike module.
+// To JSON-encode your object, you can pass it to `Standards.JSON.encode`
+// or call `encode_json` on it.
+//
+// To decode a JSON string, first pass it to `Standards.JSON.decode`,
+// and then pass the result to `<YourClass>_from_JSON`.
+// It will return an instance of <YourClass>.
+// Bear in mind that these functions have unexpected behavior,
+// and will likely throw an error, if the JSON string does not
+// match the expected interface, even if the JSON itself is valid.
+
+class TopLevel {
+    string          code;             // json: "code"
+    DateTime        date_time;        // json: "dateTime"
+    EnumValues      enum_values;      // json: "enumValues"
+    FormatException format_exception; // json: "formatException"
+    RegExp          reg_exp;          // json: "regExp"
+    Status          status;           // json: "status"
+    string          timestamp;        // json: "timestamp"
+
+    string encode_json() {
+        mapping(string:mixed) json = ([
+            "code" : code,
+            "dateTime" : date_time,
+            "enumValues" : enum_values,
+            "formatException" : format_exception,
+            "regExp" : reg_exp,
+            "status" : status,
+            "timestamp" : timestamp,
+        ]);
+
+        return Standards.JSON.encode(json);
+    }
+}
+
+TopLevel TopLevel_from_JSON(mixed json) {
+    TopLevel retval = TopLevel();
+
+    if (sizeof(json["code"]) < 1) error("String too short");
+    if (!Regexp("^[a-z]+$")->match(json["code"])) error("String does not match pattern");
+    retval.code = json["code"];
+    retval.date_time = json["dateTime"];
+    retval.enum_values = json["enumValues"];
+    retval.format_exception = json["formatException"];
+    retval.reg_exp = json["regExp"];
+    retval.status = Status_from_JSON(json["status"]);
+    retval.timestamp = json["timestamp"];
+
+    return retval;
+}
+
+class DateTime {
+    int value; // json: "value"
+
+    string encode_json() {
+        mapping(string:mixed) json = ([
+            "value" : value,
+        ]);
+
+        return Standards.JSON.encode(json);
+    }
+}
+
+DateTime DateTime_from_JSON(mixed json) {
+    DateTime retval = DateTime();
+
+    if (!intp(json["value"])) error("Expected integer");
+    retval.value = json["value"];
+
+    return retval;
+}
+
+class EnumValues {
+    string label; // json: "label"
+
+    string encode_json() {
+        mapping(string:mixed) json = ([
+            "label" : label,
+        ]);
+
+        return Standards.JSON.encode(json);
+    }
+}
+
+EnumValues EnumValues_from_JSON(mixed json) {
+    EnumValues retval = EnumValues();
+
+    retval.label = json["label"];
+
+    return retval;
+}
+
+class FormatException {
+    int count; // json: "count"
+
+    string encode_json() {
+        mapping(string:mixed) json = ([
+            "count" : count,
+        ]);
+
+        return Standards.JSON.encode(json);
+    }
+}
+
+FormatException FormatException_from_JSON(mixed json) {
+    FormatException retval = FormatException();
+
+    if (!intp(json["count"])) error("Expected integer");
+    retval.count = json["count"];
+
+    return retval;
+}
+
+class RegExp {
+    bool active; // json: "active"
+
+    string encode_json() {
+        mapping(string:mixed) json = ([
+            "active" : active,
+        ]);
+
+        return Standards.JSON.encode(json);
+    }
+}
+
+RegExp RegExp_from_JSON(mixed json) {
+    RegExp retval = RegExp();
+
+    if (json["active"] != Standards.JSON.true && json["active"] != Standards.JSON.false) error("Expected bool");
+    retval.active = json["active"];
+
+    return retval;
+}
+
+enum Status {
+    READY = "ready", // json: "ready"
+    DONE = "done",   // json: "done"
+}
+
+Status Status_from_JSON(mixed json) {
+    if(json&&json != "ready"&&json != "done")error("enum");return json;
+}
diff --git a/head/schema-python/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.py b/head/schema-python/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.py
new file mode 100644
index 0000000..ed8330c
--- /dev/null
+++ b/head/schema-python/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.py
@@ -0,0 +1,149 @@
+import datetime
+from dataclasses import dataclass
+from typing import Any, TypeVar, Type, cast
+from enum import Enum
+import dateutil.parser
+
+
+T = TypeVar("T")
+EnumT = TypeVar("EnumT", bound=Enum)
+
+
+def from_int(x: Any) -> int:
+    assert isinstance(x, int) and not isinstance(x, bool)
+    return x
+
+
+def from_str(x: Any) -> str:
+    assert isinstance(x, str)
+    return x
+
+
+def from_bool(x: Any) -> bool:
+    assert isinstance(x, bool)
+    return x
+
+
+def from_datetime(x: Any) -> datetime.datetime:
+    return dateutil.parser.parse(x)
+
+
+def to_class(c: Type[T], x: Any) -> dict:
+    assert isinstance(x, c)
+    return cast(Any, x).to_dict()
+
+
+def to_enum(c: Type[EnumT], x: Any) -> EnumT:
+    assert isinstance(x, c)
+    return x.value
+
+
+@dataclass
+class DateTime:
+    value: int
+
+    @staticmethod
+    def from_dict(obj: Any) -> 'DateTime':
+        assert isinstance(obj, dict)
+        value = from_int(obj.get("value"))
+        return DateTime(value)
+
+    def to_dict(self) -> dict:
+        result: dict = {}
+        result["value"] = from_int(self.value)
+        return result
+
+
+@dataclass
+class EnumValues:
+    label: str
+
+    @staticmethod
+    def from_dict(obj: Any) -> 'EnumValues':
+        assert isinstance(obj, dict)
+        label = from_str(obj.get("label"))
+        return EnumValues(label)
+
+    def to_dict(self) -> dict:
+        result: dict = {}
+        result["label"] = from_str(self.label)
+        return result
+
+
+@dataclass
+class FormatException:
+    count: int
+
+    @staticmethod
+    def from_dict(obj: Any) -> 'FormatException':
+        assert isinstance(obj, dict)
+        count = from_int(obj.get("count"))
+        return FormatException(count)
+
+    def to_dict(self) -> dict:
+        result: dict = {}
+        result["count"] = from_int(self.count)
+        return result
+
+
+@dataclass
+class RegExp:
+    active: bool
+
+    @staticmethod
+    def from_dict(obj: Any) -> 'RegExp':
+        assert isinstance(obj, dict)
+        active = from_bool(obj.get("active"))
+        return RegExp(active)
+
+    def to_dict(self) -> dict:
+        result: dict = {}
+        result["active"] = from_bool(self.active)
+        return result
+
+
+class Status(Enum):
+    READY = "ready"
+    DONE = "done"
+
+
+@dataclass
+class TopLevel:
+    code: str
+    date_time: DateTime
+    enum_values: EnumValues
+    format_exception: FormatException
+    reg_exp: RegExp
+    status: Status
+    timestamp: datetime.datetime
+
+    @staticmethod
+    def from_dict(obj: Any) -> 'TopLevel':
+        assert isinstance(obj, dict)
+        code = from_str(obj.get("code"))
+        date_time = DateTime.from_dict(obj.get("dateTime"))
+        enum_values = EnumValues.from_dict(obj.get("enumValues"))
+        format_exception = FormatException.from_dict(obj.get("formatException"))
+        reg_exp = RegExp.from_dict(obj.get("regExp"))
+        status = Status(obj.get("status"))
+        timestamp = from_datetime(obj.get("timestamp"))
+        return TopLevel(code, date_time, enum_values, format_exception, reg_exp, status, timestamp)
+
+    def to_dict(self) -> dict:
+        result: dict = {}
+        result["code"] = from_str(self.code)
+        result["dateTime"] = to_class(DateTime, self.date_time)
+        result["enumValues"] = to_class(EnumValues, self.enum_values)
+        result["formatException"] = to_class(FormatException, self.format_exception)
+        result["regExp"] = to_class(RegExp, self.reg_exp)
+        result["status"] = to_enum(Status, self.status)
+        result["timestamp"] = self.timestamp.isoformat()
+        return result
+
+
+def top_level_from_dict(s: Any) -> TopLevel:
+    return TopLevel.from_dict(s)
+
+
+def top_level_to_dict(x: TopLevel) -> Any:
+    return to_class(TopLevel, x)
diff --git a/head/schema-ruby/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.rb b/head/schema-ruby/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.rb
new file mode 100644
index 0000000..e53771e
--- /dev/null
+++ b/head/schema-ruby/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.rb
@@ -0,0 +1,171 @@
+# This code may look unusually verbose for Ruby (and it is), but
+# it performs some subtle and complex validation of JSON data.
+#
+# To parse this JSON, add 'dry-struct' and 'dry-types' gems, then do:
+#
+#   top_level = TopLevel.from_json! "{…}"
+#   puts top_level.reg_exp.active
+#
+# If from_json! succeeds, the value returned matches the schema.
+
+require 'json'
+require 'dry-types'
+require 'dry-struct'
+
+module Types
+  include Dry.Types(default: :nominal)
+
+  Integer = Strict::Integer
+  Bool    = Strict::Bool
+  Hash    = Strict::Hash
+  String  = Strict::String
+  Status  = Strict::String.enum("ready", "done")
+end
+
+class DateTime < Dry::Struct
+  attribute :value, Types::Integer
+
+  def self.from_dynamic!(d)
+    d = Types::Hash[d]
+    new(
+      value: d.fetch("value"),
+    )
+  end
+
+  def self.from_json!(json)
+    from_dynamic!(JSON.parse(json))
+  end
+
+  def to_dynamic
+    {
+      "value" => value,
+    }
+  end
+
+  def to_json(options = nil)
+    JSON.generate(to_dynamic, options)
+  end
+end
+
+class EnumValues < Dry::Struct
+  attribute :label, Types::String
+
+  def self.from_dynamic!(d)
+    d = Types::Hash[d]
+    new(
+      label: d.fetch("label"),
+    )
+  end
+
+  def self.from_json!(json)
+    from_dynamic!(JSON.parse(json))
+  end
+
+  def to_dynamic
+    {
+      "label" => label,
+    }
+  end
+
+  def to_json(options = nil)
+    JSON.generate(to_dynamic, options)
+  end
+end
+
+class FormatException < Dry::Struct
+  attribute :count, Types::Integer
+
+  def self.from_dynamic!(d)
+    d = Types::Hash[d]
+    new(
+      count: d.fetch("count"),
+    )
+  end
+
+  def self.from_json!(json)
+    from_dynamic!(JSON.parse(json))
+  end
+
+  def to_dynamic
+    {
+      "count" => count,
+    }
+  end
+
+  def to_json(options = nil)
+    JSON.generate(to_dynamic, options)
+  end
+end
+
+class RegExp < Dry::Struct
+  attribute :active, Types::Bool
+
+  def self.from_dynamic!(d)
+    d = Types::Hash[d]
+    new(
+      active: d.fetch("active"),
+    )
+  end
+
+  def self.from_json!(json)
+    from_dynamic!(JSON.parse(json))
+  end
+
+  def to_dynamic
+    {
+      "active" => active,
+    }
+  end
+
+  def to_json(options = nil)
+    JSON.generate(to_dynamic, options)
+  end
+end
+
+module Status
+  Ready = "ready"
+  Done  = "done"
+end
+
+class TopLevel < Dry::Struct
+  attribute :code,             Types::String.constrained(min_size: 1).constrained(format: Regexp.new("^[a-z]+$"))
+  attribute :date_time,        DateTime
+  attribute :enum_values,      EnumValues
+  attribute :format_exception, FormatException
+  attribute :reg_exp,          RegExp
+  attribute :status,           Types::Status
+  attribute :timestamp,        Types::String.constrained(format: /\A\d{4}-\d\d-\d\dT\d\d:\d\d:\d\d(?:\.\d+)?(?:Z|[+-]\d\d:\d\d)\z/i)
+
+  def self.from_dynamic!(d)
+    d = Types::Hash[d]
+    new(
+      code:             d.fetch("code"),
+      date_time:        DateTime.from_dynamic!(d.fetch("dateTime")),
+      enum_values:      EnumValues.from_dynamic!(d.fetch("enumValues")),
+      format_exception: FormatException.from_dynamic!(d.fetch("formatException")),
+      reg_exp:          RegExp.from_dynamic!(d.fetch("regExp")),
+      status:           d.fetch("status"),
+      timestamp:        d.fetch("timestamp"),
+    )
+  end
+
+  def self.from_json!(json)
+    from_dynamic!(JSON.parse(json))
+  end
+
+  def to_dynamic
+    {
+      "code"            => code,
+      "dateTime"        => date_time.to_dynamic,
+      "enumValues"      => enum_values.to_dynamic,
+      "formatException" => format_exception.to_dynamic,
+      "regExp"          => reg_exp.to_dynamic,
+      "status"          => status,
+      "timestamp"       => timestamp,
+    }
+  end
+
+  def to_json(options = nil)
+    JSON.generate(to_dynamic, options)
+  end
+end
diff --git a/head/schema-rust/test/inputs/schema/dart-runtime-type-names.schema/default/module_under_test.rs b/head/schema-rust/test/inputs/schema/dart-runtime-type-names.schema/default/module_under_test.rs
new file mode 100644
index 0000000..a6f1d16
--- /dev/null
+++ b/head/schema-rust/test/inputs/schema/dart-runtime-type-names.schema/default/module_under_test.rs
@@ -0,0 +1,60 @@
+// Example code that deserializes and serializes the model.
+// extern crate serde;
+// #[macro_use]
+// extern crate serde_derive;
+// extern crate serde_json;
+//
+// use generated_module::TopLevel;
+//
+// fn main() {
+//     let json = r#"{"answer": 42}"#;
+//     let model: TopLevel = serde_json::from_str(&json).unwrap();
+// }
+
+use serde::{Serialize, Deserialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct TopLevel {
+    pub code: String,
+
+    pub date_time: DateTime,
+
+    pub enum_values: EnumValues,
+
+    pub format_exception: FormatException,
+
+    pub reg_exp: RegExp,
+
+    pub status: Status,
+
+    pub timestamp: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DateTime {
+    pub value: i64,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct EnumValues {
+    pub label: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct FormatException {
+    pub count: i64,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct RegExp {
+    pub active: bool,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum Status {
+    Ready,
+
+    Done,
+}
diff --git a/head/schema-scala3/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.scala b/head/schema-scala3/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.scala
new file mode 100644
index 0000000..4f97ab6
--- /dev/null
+++ b/head/schema-scala3/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.scala
@@ -0,0 +1,48 @@
+package quicktype
+
+import io.circe.syntax._
+import io.circe._
+import cats.syntax.functor._
+
+// If a union has a null in, then we'll need this too... 
+type NullValue = None.type
+
+case class TopLevel (
+    val code : String,
+    val dateTime : DateTime,
+    val enumValues : EnumValues,
+    val formatException : FormatException,
+    val regExp : RegExp,
+    val status : Status,
+    val timestamp : java.time.Instant
+) derives Encoder.AsObject, Decoder
+
+case class DateTime (
+    val value : Long
+) derives Encoder.AsObject, Decoder
+
+case class EnumValues (
+    val label : String
+) derives Encoder.AsObject, Decoder
+
+case class FormatException (
+    val count : Long
+) derives Encoder.AsObject, Decoder
+
+case class RegExp (
+    val active : Boolean
+) derives Encoder.AsObject, Decoder
+
+enum Status : 
+    case Ready
+    case Done
+
+given Decoder[Status] = Decoder.decodeString.emap {
+    case "ready" => scala.Right(Status.Ready)
+    case "done" => scala.Right(Status.Done)
+    case other => scala.Left("invalid Status: " + other)
+}
+given Encoder[Status] = Encoder.encodeString.contramap {
+    case Status.Ready => "ready"
+    case Status.Done => "done"
+}
diff --git a/head/schema-scala3-upickle/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.scala b/head/schema-scala3-upickle/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.scala
new file mode 100644
index 0000000..1db190e
--- /dev/null
+++ b/head/schema-scala3-upickle/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.scala
@@ -0,0 +1,110 @@
+package quicktype
+
+// Custom pickler so that missing keys and JSON nulls both read as None,
+// and None is left out when writing (upickle's default for Option is a
+// JSON array).
+object OptionPickler extends upickle.AttributeTagged:
+    import upickle.default.Writer
+    import upickle.default.Reader
+    override implicit def OptionWriter[T: Writer]: Writer[Option[T]] =
+        implicitly[Writer[T]].comap[Option[T]] {
+            case None => null.asInstanceOf[T]
+            case Some(x) => x
+        }
+
+    override implicit def OptionReader[T: Reader]: Reader[Option[T]] = {
+        new Reader.Delegate[Any, Option[T]](implicitly[Reader[T]].map(Some(_))){
+        override def visitNull(index: Int) = None
+        }
+    }
+end OptionPickler
+
+// If a union has a null in, then we'll need this too...
+type NullValue = None.type
+given OptionPickler.ReadWriter[NullValue] = OptionPickler.readwriter[ujson.Value].bimap[NullValue](
+    _ => ujson.Null,
+    json => if json.isNull then None else throw new upickle.core.Abort("not null")
+)
+given OptionPickler.ReadWriter[java.time.Instant] = OptionPickler.readwriter[String].bimap(_.toString, java.time.Instant.parse)
+
+object JsonExt:
+    val valueReader = OptionPickler.readwriter[ujson.Value]
+
+    // upickle's built-in primitive readers are lenient -- the numeric and
+    // boolean readers accept strings, and the string reader accepts
+    // numbers and booleans -- so untagged unions need strict readers to
+    // pick the right member.
+    val strictString: OptionPickler.Reader[String] = valueReader.map {
+        case ujson.Str(s) => s
+        case json => throw new upickle.core.Abort("expected string, got " + json)
+    }
+    val strictLong: OptionPickler.Reader[Long] = valueReader.map {
+        case ujson.Num(n) if n.isWhole => n.toLong
+        case json => throw new upickle.core.Abort("expected integer, got " + json)
+    }
+    val strictDouble: OptionPickler.Reader[Double] = valueReader.map {
+        case ujson.Num(n) => n
+        case json => throw new upickle.core.Abort("expected number, got " + json)
+    }
+    val strictBoolean: OptionPickler.Reader[Boolean] = valueReader.map {
+        case ujson.Bool(b) => b
+        case json => throw new upickle.core.Abort("expected boolean, got " + json)
+    }
+
+    def badMerge[T](r1: => OptionPickler.Reader[?], rest: OptionPickler.Reader[?]*): OptionPickler.Reader[T] = valueReader.map { json =>
+        var t: T | Null = null
+        val stack       = Vector.newBuilder[Throwable]
+        (r1 +: rest).foreach { reader =>
+            if t == null then
+            try
+                t = OptionPickler.read[T](json, trace = true)(using reader.asInstanceOf[OptionPickler.Reader[T]])
+            catch
+                case exc => stack += exc
+        }
+        if t != null then t.nn else throw new Exception(json.toString(), stack.result().headOption.getOrElse(null))
+    }
+end JsonExt
+given OptionPickler.Reader[Long] = JsonExt.strictLong
+
+
+case class TopLevel (
+    val code : String,
+    val dateTime : DateTime,
+    val enumValues : EnumValues,
+    val formatException : FormatException,
+    val regExp : RegExp,
+    val status : Status,
+    val timestamp : java.time.Instant
+) derives OptionPickler.ReadWriter
+
+case class DateTime (
+    val value : Long
+) derives OptionPickler.ReadWriter
+
+case class EnumValues (
+    val label : String
+) derives OptionPickler.ReadWriter
+
+case class FormatException (
+    val count : Long
+) derives OptionPickler.ReadWriter
+
+case class RegExp (
+    val active : Boolean
+) derives OptionPickler.ReadWriter
+
+enum Status : 
+    case Ready
+    case Done
+
+given OptionPickler.ReadWriter[Status] = OptionPickler.readwriter[String].bimap[Status](
+    {
+        case Status.Ready => "ready"
+        case Status.Done => "done"
+    },
+    {
+        case "ready" => Status.Ready
+        case "done" => Status.Done
+        case other => throw new upickle.core.Abort("invalid Status: " + other)
+    }
+)
diff --git a/head/schema-schema/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.schema b/head/schema-schema/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.schema
new file mode 100644
index 0000000..8a44a89
--- /dev/null
+++ b/head/schema-schema/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.schema
@@ -0,0 +1,106 @@
+{
+    "$schema": "http://json-schema.org/draft-06/schema#",
+    "$ref": "#/definitions/TopLevel",
+    "definitions": {
+        "TopLevel": {
+            "type": "object",
+            "additionalProperties": false,
+            "properties": {
+                "code": {
+                    "type": "string",
+                    "minLength": 1,
+                    "pattern": "^[a-z]+$"
+                },
+                "dateTime": {
+                    "$ref": "#/definitions/DateTime"
+                },
+                "enumValues": {
+                    "$ref": "#/definitions/EnumValues"
+                },
+                "formatException": {
+                    "$ref": "#/definitions/FormatException"
+                },
+                "regExp": {
+                    "$ref": "#/definitions/RegExp"
+                },
+                "status": {
+                    "$ref": "#/definitions/Status"
+                },
+                "timestamp": {
+                    "type": "string",
+                    "format": "date-time"
+                }
+            },
+            "required": [
+                "code",
+                "dateTime",
+                "enumValues",
+                "formatException",
+                "regExp",
+                "status",
+                "timestamp"
+            ],
+            "title": "TopLevel"
+        },
+        "DateTime": {
+            "type": "object",
+            "additionalProperties": {},
+            "properties": {
+                "value": {
+                    "type": "integer"
+                }
+            },
+            "required": [
+                "value"
+            ],
+            "title": "DateTime"
+        },
+        "EnumValues": {
+            "type": "object",
+            "additionalProperties": {},
+            "properties": {
+                "label": {
+                    "type": "string"
+                }
+            },
+            "required": [
+                "label"
+            ],
+            "title": "EnumValues"
+        },
+        "FormatException": {
+            "type": "object",
+            "additionalProperties": {},
+            "properties": {
+                "count": {
+                    "type": "integer"
+                }
+            },
+            "required": [
+                "count"
+            ],
+            "title": "FormatException"
+        },
+        "RegExp": {
+            "type": "object",
+            "additionalProperties": {},
+            "properties": {
+                "active": {
+                    "type": "boolean"
+                }
+            },
+            "required": [
+                "active"
+            ],
+            "title": "RegExp"
+        },
+        "Status": {
+            "type": "string",
+            "enum": [
+                "ready",
+                "done"
+            ],
+            "title": "Status"
+        }
+    }
+}
diff --git a/head/schema-swift/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.swift b/head/schema-swift/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.swift
new file mode 100644
index 0000000..ed5871a
--- /dev/null
+++ b/head/schema-swift/test/inputs/schema/dart-runtime-type-names.schema/default/quicktype.swift
@@ -0,0 +1,291 @@
+// This file was generated from JSON Schema using quicktype, do not modify it directly.
+// To parse the JSON, add this file to your project and do:
+//
+//   let topLevel = try TopLevel(json)
+
+import Foundation
+
+// MARK: - TopLevel
+struct TopLevel: Codable {
+    let code: String
+    let dateTime: DateTime
+    let enumValues: EnumValues
+    let formatException: FormatException
+    let regExp: RegExp
+    let status: Status
+    let timestamp: Date
+
+    enum CodingKeys: String, CodingKey {
+        case code = "code"
+        case dateTime = "dateTime"
+        case enumValues = "enumValues"
+        case formatException = "formatException"
+        case regExp = "regExp"
+        case status = "status"
+        case timestamp = "timestamp"
+    }
+}
+
+// MARK: TopLevel convenience initializers and mutators
+
+extension TopLevel {
+    init(data: Data) throws {
+        self = try newJSONDecoder().decode(TopLevel.self, from: data)
+    }
+
+    init(_ json: String, using encoding: String.Encoding = .utf8) throws {
+        guard let data = json.data(using: encoding) else {
+            throw NSError(domain: "JSONDecoding", code: 0, userInfo: nil)
+        }
+        try self.init(data: data)
+    }
+
+    init(fromURL url: URL) throws {
+        try self.init(data: try Data(contentsOf: url))
+    }
+
+    func with(
+        code: String? = nil,
+        dateTime: DateTime? = nil,
+        enumValues: EnumValues? = nil,
+        formatException: FormatException? = nil,
+        regExp: RegExp? = nil,
+        status: Status? = nil,
+        timestamp: Date? = nil
+    ) -> TopLevel {
+        return TopLevel(
+            code: code ?? self.code,
+            dateTime: dateTime ?? self.dateTime,
+            enumValues: enumValues ?? self.enumValues,
+            formatException: formatException ?? self.formatException,
+            regExp: regExp ?? self.regExp,
+            status: status ?? self.status,
+            timestamp: timestamp ?? self.timestamp
+        )
+    }
+
+    func jsonData() throws -> Data {
+        return try newJSONEncoder().encode(self)
+    }
+
+    func jsonString(encoding: String.Encoding = .utf8) throws -> String? {
+        return String(data: try self.jsonData(), encoding: encoding)
+    }
+}
+
+// MARK: - DateTime
+struct DateTime: Codable {
+    let value: Int
+
+    enum CodingKeys: String, CodingKey {
+        case value = "value"
+    }
+}
+
+// MARK: DateTime convenience initializers and mutators
+
+extension DateTime {
+    init(data: Data) throws {
+        self = try newJSONDecoder().decode(DateTime.self, from: data)
+    }
+
+    init(_ json: String, using encoding: String.Encoding = .utf8) throws {
+        guard let data = json.data(using: encoding) else {
+            throw NSError(domain: "JSONDecoding", code: 0, userInfo: nil)
+        }
+        try self.init(data: data)
+    }
+
+    init(fromURL url: URL) throws {
+        try self.init(data: try Data(contentsOf: url))
+    }
+
+    func with(
+        value: Int? = nil
+    ) -> DateTime {
+        return DateTime(
+            value: value ?? self.value
+        )
+    }
+
+    func jsonData() throws -> Data {
+        return try newJSONEncoder().encode(self)
+    }
+
+    func jsonString(encoding: String.Encoding = .utf8) throws -> String? {
+        return String(data: try self.jsonData(), encoding: encoding)
+    }
+}
+
+// MARK: - EnumValues
+struct EnumValues: Codable {
+    let label: String
+
+    enum CodingKeys: String, CodingKey {
+        case label = "label"
+    }
+}
+
+// MARK: EnumValues convenience initializers and mutators
+
+extension EnumValues {
+    init(data: Data) throws {
+        self = try newJSONDecoder().decode(EnumValues.self, from: data)
+    }
+
+    init(_ json: String, using encoding: String.Encoding = .utf8) throws {
+        guard let data = json.data(using: encoding) else {
+            throw NSError(domain: "JSONDecoding", code: 0, userInfo: nil)
+        }
+        try self.init(data: data)
+    }
+
+    init(fromURL url: URL) throws {
+        try self.init(data: try Data(contentsOf: url))
+    }
+
+    func with(
+        label: String? = nil
+    ) -> EnumValues {
+        return EnumValues(
+            label: label ?? self.label
+        )
+    }
+
+    func jsonData() throws -> Data {
+        return try newJSONEncoder().encode(self)
+    }
+
+    func jsonString(encoding: String.Encoding = .utf8) throws -> String? {
+        return String(data: try self.jsonData(), encoding: encoding)
+    }
+}
+
+// MARK: - FormatException
+struct FormatException: Codable {
+    let count: Int
+
+    enum CodingKeys: String, CodingKey {
+        case count = "count"
+    }
+}
+
+// MARK: FormatException convenience initializers and mutators
+
+extension FormatException {
+    init(data: Data) throws {
+        self = try newJSONDecoder().decode(FormatException.self, from: data)
+    }
+
+    init(_ json: String, using encoding: String.Encoding = .utf8) throws {
+        guard let data = json.data(using: encoding) else {
+            throw NSError(domain: "JSONDecoding", code: 0, userInfo: nil)
+        }
+        try self.init(data: data)
+    }
+
+    init(fromURL url: URL) throws {
+        try self.init(data: try Data(contentsOf: url))
+    }
+
+    func with(
+        count: Int? = nil
+    ) -> FormatException {
+        return FormatException(
+            count: count ?? self.count
+        )
+    }
+
+    func jsonData() throws -> Data {
+        return try newJSONEncoder().encode(self)
+    }
+
+    func jsonString(encoding: String.Encoding = .utf8) throws -> String? {
+        return String(data: try self.jsonData(), encoding: encoding)
+    }
+}
+
+// MARK: - RegExp
+struct RegExp: Codable {
+    let active: Bool
+
+    enum CodingKeys: String, CodingKey {
+        case active = "active"
+    }
+}
+
+// MARK: RegExp convenience initializers and mutators
+
+extension RegExp {
+    init(data: Data) throws {
+        self = try newJSONDecoder().decode(RegExp.self, from: data)
+    }
+
+    init(_ json: String, using encoding: String.Encoding = .utf8) throws {
+        guard let data = json.data(using: encoding) else {
+            throw NSError(domain: "JSONDecoding", code: 0, userInfo: nil)
+        }
+        try self.init(data: data)
+    }
+
+    init(fromURL url: URL) throws {
+        try self.init(data: try Data(contentsOf: url))
+    }
+
+    func with(
+        active: Bool? = nil
+    ) -> RegExp {
+        return RegExp(
+            active: active ?? self.active
+        )
+    }
+
+    func jsonData() throws -> Data {
+        return try newJSONEncoder().encode(self)
+    }
+
+    func jsonString(encoding: String.Encoding = .utf8) throws -> String? {
+        return String(data: try self.jsonData(), encoding: encoding)
+    }
+}
+
+enum Status: String, Codable {
+    case ready = "ready"
+    case done = "done"
+}
+
+// MARK: - Helper functions for creating encoders and decoders
+
+func newJSONDecoder() -> JSONDecoder {
+    let decoder = JSONDecoder()
+    decoder.dateDecodingStrategy = .custom({ (decoder) -> Date in
+        let container = try decoder.singleValueContainer()
+        let dateStr = try container.decode(String.self)
+
+        let formatter = DateFormatter()
+        formatter.calendar = Calendar(identifier: .iso8601)
+        formatter.locale = Locale(identifier: "en_US_POSIX")
+        formatter.timeZone = TimeZone(secondsFromGMT: 0)
+        formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSXXXXX"
+        if let date = formatter.date(from: dateStr) {
+            return date
+        }
+        formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssXXXXX"
+        if let date = formatter.date(from: dateStr) {
+            return date
+        }
+        throw DecodingError.typeMismatch(Date.self, DecodingError.Context(codingPath: decoder.codingPath, debugDescription: "Could not decode date"))
+    })
+    return decoder
+}
+
+func newJSONEncoder() -> JSONEncoder {
+    let encoder = JSONEncoder()
+    let formatter = DateFormatter()
+    formatter.calendar = Calendar(identifier: .iso8601)
+    formatter.locale = Locale(identifier: "en_US_POSIX")
+    formatter.timeZone = TimeZone(secondsFromGMT: 0)
+    formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSSSSXXXXX"
+    encoder.dateEncodingStrategy = .formatted(formatter)
+    return encoder
+}
diff --git a/head/schema-typescript/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.ts b/head/schema-typescript/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.ts
new file mode 100644
index 0000000..eb0a9b6
--- /dev/null
+++ b/head/schema-typescript/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.ts
@@ -0,0 +1,254 @@
+// To parse this data:
+//
+//   import { Convert, TopLevel } from "./TopLevel";
+//
+//   const topLevel = Convert.toTopLevel(json);
+//
+// These functions will throw an error if the JSON doesn't
+// match the expected interface, even if the JSON is valid.
+
+export interface TopLevel {
+    code:            string;
+    dateTime:        DateTime;
+    enumValues:      EnumValues;
+    formatException: FormatException;
+    regExp:          RegExp;
+    status:          Status;
+    timestamp:       Date;
+}
+
+export interface DateTime {
+    value: number;
+    [property: string]: unknown | number;
+}
+
+export interface EnumValues {
+    label: string;
+    [property: string]: unknown | string;
+}
+
+export interface FormatException {
+    count: number;
+    [property: string]: unknown | number;
+}
+
+export interface RegExp {
+    active: boolean;
+    [property: string]: unknown | boolean;
+}
+
+export type Status = "ready" | "done";
+
+// Converts JSON strings to/from your types
+// and asserts the results of JSON.parse at runtime
+export class Convert {
+    public static toTopLevel(json: string): TopLevel {
+        return cast(JSON.parse(json), r("TopLevel"));
+    }
+
+    public static topLevelToJson(value: TopLevel): string {
+        return JSON.stringify(uncast(value, r("TopLevel")), null, 2);
+    }
+}
+
+function invalidValue(typ: any, val: any, key: any, parent: any = ''): never {
+    const prettyTyp = prettyTypeName(typ);
+    const parentText = parent ? ` on ${parent}` : '';
+    const keyText = key ? ` for key "${key}"` : '';
+    throw Error(`Invalid value${keyText}${parentText}. Expected ${prettyTyp} but got ${JSON.stringify(val)}`);
+}
+
+function prettyTypeName(typ: any): string {
+    if (Array.isArray(typ)) {
+        if (typ.length === 2 && typ[0] === undefined) {
+            return `an optional ${prettyTypeName(typ[1])}`;
+        } else {
+            return `one of [${typ.map(a => { return prettyTypeName(a); }).join(", ")}]`;
+        }
+    } else if (typeof typ === "object" && typ.literal !== undefined) {
+        return typ.literal;
+    } else {
+        return typeof typ;
+    }
+}
+
+function jsonToJSProps(typ: any): any {
+    if (typ.jsonToJS === undefined) {
+        const map: any = {};
+        typ.props.forEach((p: any) => map[p.json] = { key: p.js, typ: p.typ });
+        typ.jsonToJS = map;
+    }
+    return typ.jsonToJS;
+}
+
+function jsToJSONProps(typ: any): any {
+    if (typ.jsToJSON === undefined) {
+        const map: any = {};
+        typ.props.forEach((p: any) => map[p.js] = { key: p.json, typ: p.typ });
+        typ.jsToJSON = map;
+    }
+    return typ.jsToJSON;
+}
+
+function transform(val: any, typ: any, getProps: any, key: any = '', parent: any = ''): any {
+    function transformPrimitive(typ: string, val: any): any {
+        if (typeof typ === typeof val) return val;
+        return invalidValue(typ, val, key, parent);
+    }
+
+    function transformUnion(typs: any[], val: any): any {
+        // val must validate against one typ in typs
+        const l = typs.length;
+        for (let i = 0; i < l; i++) {
+            const typ = typs[i];
+            try {
+                return transform(val, typ, getProps);
+            } catch (_) {}
+        }
+        return invalidValue(typs, val, key, parent);
+    }
+
+    function transformEnum(cases: string[], val: any): any {
+        if (cases.indexOf(val) !== -1) return val;
+        return invalidValue(cases.map(a => { return l(a); }), val, key, parent);
+    }
+
+    function transformArray(typ: any, val: any): any {
+        // val must be an array with no invalid elements
+        if (!Array.isArray(val)) return invalidValue(l("array"), val, key, parent);
+
+        return val.map(el => transform(el, typ, getProps));
+    }
+
+    function transformDate(val: any): any {
+        if (val === null) {
+            return null;
+        }
+        const d = new Date(val);
+        if (isNaN(d.valueOf())) {
+            return invalidValue(l("Date"), val, key, parent);
+        }
+        return d;
+    }
+
+    function transformObject(props: { [k: string]: any }, additional: any, val: any): any {
+        if (val === null || typeof val !== "object" || Array.isArray(val)) {
+            return invalidValue(l(ref || "object"), val, key, parent);
+        }
+        const result: any = {};
+        Object.getOwnPropertyNames(props).forEach(key => {
+            const prop = props[key];
+            const v = Object.prototype.hasOwnProperty.call(val, key) ? val[key] : undefined;
+            result[prop.key] = transform(v, prop.typ, getProps, key, ref);
+        });
+        Object.getOwnPropertyNames(val).forEach(key => {
+            if (!Object.prototype.hasOwnProperty.call(props, key)) {
+                result[key] = transform(val[key], additional, getProps, key, ref);
+            }
+        });
+        return result;
+    }
+
+    if (typ === "any") return val;
+    if (typ === null) {
+        if (val === null) return val;
+        return invalidValue(typ, val, key, parent);
+    }
+    if (typ === false) return invalidValue(typ, val, key, parent);
+    let ref: any = undefined;
+    while (typeof typ === "object" && typ.ref !== undefined) {
+        ref = typ.ref;
+        typ = typeMap[typ.ref];
+    }
+    if (Array.isArray(typ)) return transformEnum(typ, val);
+    if (typeof typ === "object") {
+        return typ.hasOwnProperty("pattern")      ? typeof val === "string" && new RegExp(typ.pattern).test(val) ? val : invalidValue(typ, val, key, parent)
+            : typ.hasOwnProperty("string")       ? typeof val === "string" && (typ.min === undefined || val.length >= typ.min) && (typ.max === undefined || val.length <= typ.max) ? transform(val, typ.string, getProps, key, parent) : invalidValue(typ, val, key, parent)
+            : typ.hasOwnProperty("number")       ? typeof val === "number" && (typ.min === undefined || val >= typ.min) && (typ.max === undefined || val <= typ.max) ? transform(val, typ.number, getProps, key, parent) : invalidValue(typ, val, key, parent)
+            : typ.hasOwnProperty("integer")      ? typeof val === "number" && val % 1 === 0 ? val : invalidValue(l("integer"), val, key, parent)
+            : typ.hasOwnProperty("unionMembers") ? transformUnion(typ.unionMembers, val)
+            : typ.hasOwnProperty("arrayItems")    ? transformArray(typ.arrayItems, val)
+            : typ.hasOwnProperty("props")         ? transformObject(getProps(typ), typ.additional, val)
+            : invalidValue(typ, val, key, parent);
+    }
+    // Numbers can be parsed by Date but shouldn't be.
+    if (typ === Date && typeof val !== "number") return transformDate(val);
+    return transformPrimitive(typ, val);
+}
+
+function cast<T>(val: any, typ: any): T {
+    return transform(val, typ, jsonToJSProps);
+}
+
+function uncast<T>(val: T, typ: any): any {
+    return transform(val, typ, jsToJSONProps);
+}
+
+function l(typ: any) {
+    return { literal: typ };
+}
+
+function a(typ: any) {
+    return { arrayItems: typ };
+}
+
+function i(typ: any) {
+    return { integer: typ };
+}
+
+function p(pattern: any) {
+    return { pattern };
+}
+
+function s(typ: any, min: any, max: any) {
+    return { string: typ, min, max };
+}
+
+function n(typ: any, min: any, max: any) {
+    return { number: typ, min, max };
+}
+
+function u(...typs: any[]) {
+    return { unionMembers: typs };
+}
+
+function o(props: any[], additional: any) {
+    return { props, additional };
+}
+
+function m(additional: any) {
+    const props: any[] = [];
+    return { props, additional };
+}
+
+function r(name: string) {
+    return { ref: name };
+}
+
+const typeMap: any = {
+    "TopLevel": o([
+        { json: "code", js: "code", typ: s(p("^[a-z]+$"), 1, undefined) },
+        { json: "dateTime", js: "dateTime", typ: r("DateTime") },
+        { json: "enumValues", js: "enumValues", typ: r("EnumValues") },
+        { json: "formatException", js: "formatException", typ: r("FormatException") },
+        { json: "regExp", js: "regExp", typ: r("RegExp") },
+        { json: "status", js: "status", typ: r("Status") },
+        { json: "timestamp", js: "timestamp", typ: Date },
+    ], false),
+    "DateTime": o([
+        { json: "value", js: "value", typ: i(0) },
+    ], "any"),
+    "EnumValues": o([
+        { json: "label", js: "label", typ: "" },
+    ], "any"),
+    "FormatException": o([
+        { json: "count", js: "count", typ: i(0) },
+    ], "any"),
+    "RegExp": o([
+        { json: "active", js: "active", typ: true },
+    ], "any"),
+    "Status": [
+        "ready",
+        "done",
+    ],
+};
diff --git a/head/schema-typescript-effect-schema/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.ts b/head/schema-typescript-effect-schema/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.ts
new file mode 100644
index 0000000..e3da1d2
--- /dev/null
+++ b/head/schema-typescript-effect-schema/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.ts
@@ -0,0 +1,34 @@
+import * as S from "effect/Schema";
+
+
+export const Status = S.Literal(
+    "ready",
+    "done",
+);
+export type Status = S.Schema.Type<typeof Status>;
+
+export class RegExp extends S.Class<RegExp>("RegExp")({
+    "active": S.Boolean,
+}) {}
+
+export class FormatException extends S.Class<FormatException>("FormatException")({
+    "count": S.Int,
+}) {}
+
+export class EnumValues extends S.Class<EnumValues>("EnumValues")({
+    "label": S.String,
+}) {}
+
+export class DateTime extends S.Class<DateTime>("DateTime")({
+    "value": S.Int,
+}) {}
+
+export class TopLevel extends S.Class<TopLevel>("TopLevel")({
+    "code": S.String.pipe(S.minLength(1)).pipe(S.pattern(new RegExp("^[a-z]+$"))),
+    "dateTime": DateTime,
+    "enumValues": EnumValues,
+    "formatException": FormatException,
+    "regExp": RegExp,
+    "status": Status,
+    "timestamp": S.String.pipe(S.pattern(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(?:\.\d+)?(?:Z|[+-]\d{2}:\d{2})$/)),
+}) {}
diff --git a/head/schema-typescript-zod/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.ts b/head/schema-typescript-zod/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.ts
new file mode 100644
index 0000000..fbbf2cd
--- /dev/null
+++ b/head/schema-typescript-zod/test/inputs/schema/dart-runtime-type-names.schema/default/TopLevel.ts
@@ -0,0 +1,39 @@
+import * as z from "zod";
+
+
+export const StatusSchema = z.enum([
+    "ready",
+    "done",
+]);
+export type Status = z.infer<typeof StatusSchema>;
+
+export const DateTimeSchema = z.object({
+    "value": z.number().int(),
+});
+export type DateTime = z.infer<typeof DateTimeSchema>;
+
+export const EnumValuesSchema = z.object({
+    "label": z.string(),
+});
+export type EnumValues = z.infer<typeof EnumValuesSchema>;
+
+export const FormatExceptionSchema = z.object({
+    "count": z.number().int(),
+});
+export type FormatException = z.infer<typeof FormatExceptionSchema>;
+
+export const RegExpSchema = z.object({
+    "active": z.boolean(),
+});
+export type RegExp = z.infer<typeof RegExpSchema>;
+
+export const TopLevelSchema = z.object({
+    "code": z.string().min(1).regex(new RegExp("^[a-z]+$")),
+    "dateTime": DateTimeSchema,
+    "enumValues": EnumValuesSchema,
+    "formatException": FormatExceptionSchema,
+    "regExp": RegExpSchema,
+    "status": StatusSchema,
+    "timestamp": z.coerce.date(),
+});
+export type TopLevel = z.infer<typeof TopLevelSchema>;
