diff --git a/mozilla/widget/src/gtk/nsAppShell.cpp b/mozilla/widget/src/gtk/nsAppShell.cpp
index 190603d92fd..be17fb47b6e 100644
--- a/mozilla/widget/src/gtk/nsAppShell.cpp
+++ b/mozilla/widget/src/gtk/nsAppShell.cpp
@@ -156,7 +156,7 @@ NS_METHOD nsAppShell::Spindown()
 
 //-------------------------------------------------------------------------
 //
-// GetNativeData
+// Run
 //
 //-------------------------------------------------------------------------
 NS_METHOD nsAppShell::Run()
@@ -251,6 +251,13 @@ NS_METHOD nsAppShell::DispatchNativeEvent(PRBool aRealEvent, void *aEvent)
   return NS_ERROR_FAILURE;
 }
 
+NS_METHOD nsAppShell::EventIsForModalWindow(PRBool aRealEvent, void *aEvent,
+    nsIWidget *aWidget, PRBool *aForWindow)
+{
+  *aForWindow = PR_TRUE;
+  return NS_OK;
+}
+
 NS_METHOD
 nsAppShell::GetSelectionMgr(nsISelectionMgr** aSelectionMgr)
 {
diff --git a/mozilla/widget/src/gtk/nsAppShell.h b/mozilla/widget/src/gtk/nsAppShell.h
index c56fa81f995..e94dbddf279 100644
--- a/mozilla/widget/src/gtk/nsAppShell.h
+++ b/mozilla/widget/src/gtk/nsAppShell.h
@@ -44,6 +44,8 @@ class nsAppShell : public nsIAppShell
     NS_IMETHOD          Spindown();
     NS_IMETHOD          GetNativeEvent(PRBool &aRealEvent, void *&aEvent);
     NS_IMETHOD          DispatchNativeEvent(PRBool aRealEvent, void * aEvent);
+    NS_IMETHOD          EventIsForModalWindow(PRBool aRealEvent, void *aEvent,
+                          nsIWidget *aWidget, PRBool *aForWindow);
     NS_IMETHOD		Exit();
     NS_IMETHOD		SetDispatchListener(nsDispatchListener* aDispatchListener);
     virtual void*	GetNativeData(PRUint32 aDataType);