--- moz/zipped/makefile.mk	2012-01-11 21:19:49.000000000 +0900
+++ moz/zipped/makefile.mk	2012-09-20 15:35:23.000000000 +0900
@@ -72,7 +72,8 @@
 .ENDIF
 
 $(BIN)$/mozruntime%zip : $(OS)$(COM)$(CPU)runtime.zip
-	$(COPY) $(OS)$(COM)$(CPU)runtime.zip $(BIN)$/mozruntime.zip
+	$(COPY) $(OS)$(COM)$(CPU)runtime.zip $(BIN)$/mozruntime.zip && \
+	chmod u+w $(BIN)$/mozruntime.zip
 
 # add alternative rules for universal binary moz-zips
 .IF "$(GUIBASE)" == "aqua"