diff --git a/Source/WebCore/WebCoreJava.pro b/Source/WebCore/WebCoreJava.pro
--- a/Source/WebCore/WebCoreJava.pro
+++ b/Source/WebCore/WebCoreJava.pro
@@ -2926,7 +2926,7 @@
                                --idlAttributesFile $${IDL_ATTRIBUTES_FILE} \
                                $${MOC_PREPROCESSOR}
 preprocessIdls.output = $$SUPPLEMENTAL_DEPENDENCY_FILE
-#preprocessIdls.wkAddOutputToSources = false
+preprocessIdls.wkAddOutputToSources = false
 preprocessIdls.depends = $$PWD/bindings/scripts/IDLParser.pm $$IDL_BINDINGS
 addExtraCompiler(preprocessIdls)