diff --git a/base/schema-kotlin-jackson/test/inputs/schema/minmaxlength.schema/default/TopLevel.kt b/head/schema-kotlin-jackson/test/inputs/schema/minmaxlength.schema/default/TopLevel.kt
index a9b8209..8181b64 100644
--- a/base/schema-kotlin-jackson/test/inputs/schema/minmaxlength.schema/default/TopLevel.kt
+++ b/head/schema-kotlin-jackson/test/inputs/schema/minmaxlength.schema/default/TopLevel.kt
@@ -55,6 +55,18 @@ data class TopLevel (
     @get:JsonProperty(required=true)@field:JsonProperty(required=true)
     val union: String
 ) {
+    init {
+        require(intersection.length >= 4)
+        require(intersection.length <= 5)
+        require(maxlength.length <= 5)
+        require(minlength.length >= 3)
+        require(minMaxIntersection.length >= 3)
+        require(minMaxIntersection.length <= 5)
+        require(minmaxlength.length >= 3)
+        require(minmaxlength.length <= 5)
+        require(union.length >= 3)
+        require(union.length <= 6)
+    }
     fun toJson() = mapper.writeValueAsString(this)
 
     companion object {
diff --git a/base/schema-kotlin-jackson/test/inputs/schema/optional-const-ref.schema/default/TopLevel.kt b/head/schema-kotlin-jackson/test/inputs/schema/optional-const-ref.schema/default/TopLevel.kt
index b0d2da2..4f974ae 100644
--- a/base/schema-kotlin-jackson/test/inputs/schema/optional-const-ref.schema/default/TopLevel.kt
+++ b/head/schema-kotlin-jackson/test/inputs/schema/optional-const-ref.schema/default/TopLevel.kt
@@ -35,6 +35,12 @@ data class TopLevel (
 
     val weight: Double? = null
 ) {
+    init {
+        label?.let { require(it.length >= 2) }
+        label?.let { require(it.length <= 16) }
+        require(requiredLabel.length >= 2)
+        require(requiredLabel.length <= 16)
+    }
     fun toJson() = mapper.writeValueAsString(this)
 
     companion object {
diff --git a/base/schema-kotlin-jackson/test/inputs/schema/optional-constraints.schema/default/TopLevel.kt b/head/schema-kotlin-jackson/test/inputs/schema/optional-constraints.schema/default/TopLevel.kt
index e48c806..bff320e 100644
--- a/base/schema-kotlin-jackson/test/inputs/schema/optional-constraints.schema/default/TopLevel.kt
+++ b/head/schema-kotlin-jackson/test/inputs/schema/optional-constraints.schema/default/TopLevel.kt
@@ -28,6 +28,10 @@ data class TopLevel (
     @get:JsonProperty(required=true)@field:JsonProperty(required=true)
     val reqZeroMin: Long
 ) {
+    init {
+        optString?.let { require(it.length >= 3) }
+        optString?.let { require(it.length <= 10) }
+    }
     fun toJson() = mapper.writeValueAsString(this)
 
     companion object {
diff --git a/base/schema-kotlin-jackson/test/inputs/schema/schema-constraints.schema/default/TopLevel.kt b/head/schema-kotlin-jackson/test/inputs/schema/schema-constraints.schema/default/TopLevel.kt
index f369be5..33e9bc4 100644
--- a/base/schema-kotlin-jackson/test/inputs/schema/schema-constraints.schema/default/TopLevel.kt
+++ b/head/schema-kotlin-jackson/test/inputs/schema/schema-constraints.schema/default/TopLevel.kt
@@ -25,6 +25,10 @@ data class TopLevel (
     @get:JsonProperty(required=true)@field:JsonProperty(required=true)
     val percent: Double
 ) {
+    init {
+        require(minMaxLength.length >= 5)
+        require(minMaxLength.length <= 5)
+    }
     fun toJson() = mapper.writeValueAsString(this)
 
     companion object {