diff --git a/libraries/tools/kotlin-stdlib-gen/src/generators/SourceFile.kt b/libraries/tools/kotlin-stdlib-gen/src/generators/SourceFile.kt
index 1bb4c7118de..60a1c965daf 100644
--- a/libraries/tools/kotlin-stdlib-gen/src/generators/SourceFile.kt
+++ b/libraries/tools/kotlin-stdlib-gen/src/generators/SourceFile.kt
@@ -14,7 +14,7 @@ enum class SourceFile(jvmClassName: String? = null, val multifile: Boolean = tru
 
     val name = this.name()
 
-    val jvmClassName = jvmClassName ?: this.name().capitalize()
+    val jvmClassName = jvmClassName ?: (name.capitalize() + "Kt")
 
     val fileName: String get() = "_${name.capitalize()}.kt"
 }