diff --git a/xpcom/appshell/eventloop/windows/nsIWinEvent.idl b/xpcom/appshell/eventloop/windows/nsIWinEvent.idl
index 46a898d37f97..acee50fa0de1 100644
--- a/xpcom/appshell/eventloop/windows/nsIWinEvent.idl
+++ b/xpcom/appshell/eventloop/windows/nsIWinEvent.idl
@@ -8,11 +8,11 @@
 [scriptable, uuid(2EFB5005-4508-11d3-AEDA-00A024FFC08C)]
 interface nsIWinEvent : nsIEvent
 {
-	attribute voidStar hwnd;
+	[noscript] attribute voidStar hwnd;
 	attribute unsigned long message;
 	attribute unsigned long wParam;
 	attribute unsigned long lParam;
 	attribute unsigned long time;
 	attribute long pointX;
 	attribute long pointY;
-};
\ No newline at end of file
+};