diff --git a/jps-plugin/src/org/jetbrains/jet/jps/build/KotlinBuilder.java b/jps-plugin/src/org/jetbrains/jet/jps/build/KotlinBuilder.java
index 998759523e2..02fa06e14f9 100644
--- a/jps-plugin/src/org/jetbrains/jet/jps/build/KotlinBuilder.java
+++ b/jps-plugin/src/org/jetbrains/jet/jps/build/KotlinBuilder.java
@@ -40,6 +40,7 @@ import java.io.IOException;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 import static org.jetbrains.jet.cli.common.messages.CompilerMessageSeverity.EXCEPTION;
@@ -49,6 +50,7 @@ import static org.jetbrains.jet.cli.common.messages.CompilerMessageSeverity.WARN
 public class KotlinBuilder extends ModuleLevelBuilder {
 
     private static final String KOTLIN_BUILDER_NAME = "Kotlin Builder";
+    private static final List<String> COMPILABLE_FILE_EXTENSIONS = Collections.singletonList("kt");
 
     private static final Function<JpsModule,String> MODULE_NAME = new Function<JpsModule, String>() {
         @Override
@@ -202,4 +204,9 @@ public class KotlinBuilder extends ModuleLevelBuilder {
         }
 
     }
+
+    @Override
+    public List<String> getCompilableFileExtensions() {
+        return COMPILABLE_FILE_EXTENSIONS;
+    }
 }