diff --git a/libraries/tools/kotlin-gradle-plugin-idea/src/main/kotlin/org/jetbrains/kotlin/gradle/kpm/KotlinExternalModelType.kt b/libraries/tools/kotlin-gradle-plugin-idea/src/main/kotlin/org/jetbrains/kotlin/gradle/kpm/KotlinExternalModelType.kt
index 280535241d5..37ed10e39bf 100644
--- a/libraries/tools/kotlin-gradle-plugin-idea/src/main/kotlin/org/jetbrains/kotlin/gradle/kpm/KotlinExternalModelType.kt
+++ b/libraries/tools/kotlin-gradle-plugin-idea/src/main/kotlin/org/jetbrains/kotlin/gradle/kpm/KotlinExternalModelType.kt
@@ -39,5 +39,5 @@ internal fun externalModelTypeSignature(type: KType): String {
     require(type.arguments.isEmpty()) { "Parameterized types are not supported. Found $type" }
     val classifier = requireNotNull(type.classifier) { "Expected classifier. Found $type" }
     val clazz = (classifier as? KClass<*>) ?: throw IllegalArgumentException("Expected KClass classifier. Found $classifier")
-    return clazz.qualifiedName ?: throw IllegalArgumentException("Missing qualifiedName in $type")
+    return clazz.java.name ?: throw IllegalArgumentException("Missing qualifiedName in $type")
 }