diff --git a/jps/jps-plugin/src/org/jetbrains/kotlin/jps/build/KotlinDirtySourceFilesHolder.kt b/jps/jps-plugin/src/org/jetbrains/kotlin/jps/build/KotlinDirtySourceFilesHolder.kt
index 3604d5d5d99..7665579f765 100644
--- a/jps/jps-plugin/src/org/jetbrains/kotlin/jps/build/KotlinDirtySourceFilesHolder.kt
+++ b/jps/jps-plugin/src/org/jetbrains/kotlin/jps/build/KotlinDirtySourceFilesHolder.kt
@@ -97,4 +97,4 @@ class KotlinDirtySourceFilesHolder(
 }
 
 val File.isKotlinSourceFile: Boolean
-    get() = FileUtilRt.extensionEquals(name, "kt")
+    get() = FileUtilRt.extensionEquals(name, "kt") || FileUtilRt.extensionEquals(name, "kts")