diff --git a/base/schema-kotlin/test/inputs/schema/optional-constraints.schema/default/TopLevel.kt b/head/schema-kotlin/test/inputs/schema/optional-constraints.schema/default/TopLevel.kt
index 0d711b6..b4366ba 100644
--- a/base/schema-kotlin/test/inputs/schema/optional-constraints.schema/default/TopLevel.kt
+++ b/head/schema-kotlin/test/inputs/schema/optional-constraints.schema/default/TopLevel.kt
@@ -27,6 +27,9 @@ data class TopLevel (
     init {
         optInt?.let { require(it <= 100) }
     }
+    init {
+        optPattern?.let { require(Regex("^[a-z]+\$").containsMatchIn(it)) }
+    }
     init {
         optString?.let { require(it.length >= 3) }
     }
diff --git a/base/schema-kotlin/test/inputs/schema/pattern.schema/default/TopLevel.kt b/head/schema-kotlin/test/inputs/schema/pattern.schema/default/TopLevel.kt
index 37059af..d499ccf 100644
--- a/base/schema-kotlin/test/inputs/schema/pattern.schema/default/TopLevel.kt
+++ b/head/schema-kotlin/test/inputs/schema/pattern.schema/default/TopLevel.kt
@@ -13,6 +13,15 @@ data class TopLevel (
     val pattern2: String,
     val union: String
 ) {
+    init {
+        require(Regex("a[.]*").containsMatchIn(pattern1))
+    }
+    init {
+        require(Regex("b[.]*").containsMatchIn(pattern2))
+    }
+    init {
+        require(Regex("(b[.]*)|(c[.]*)").containsMatchIn(union))
+    }
     public fun toJson() = klaxon.toJsonString(this)
 
     companion object {
diff --git a/base/schema-kotlin/test/inputs/schema/renaming-bug.schema/default/TopLevel.kt b/head/schema-kotlin/test/inputs/schema/renaming-bug.schema/default/TopLevel.kt
index 45683a2..74f5c2e 100644
--- a/base/schema-kotlin/test/inputs/schema/renaming-bug.schema/default/TopLevel.kt
+++ b/head/schema-kotlin/test/inputs/schema/renaming-bug.schema/default/TopLevel.kt
@@ -23,6 +23,9 @@ data class TopLevel (
     val fruits: List<Fruit>? = null,
     val vehicles: List<Vehicle>? = null
 ) {
+    init {
+        version?.let { require(Regex("^\\d{1,5}.{1}\\d{1,5}.{1}\\d{1,5}\$").containsMatchIn(it)) }
+    }
     public fun toJson() = klaxon.toJsonString(this)
 
     companion object {