diff --git a/mozilla/dom/src/base/nsGlobalWindow.cpp b/mozilla/dom/src/base/nsGlobalWindow.cpp
index 55e292932d3..e17612c3307 100644
--- a/mozilla/dom/src/base/nsGlobalWindow.cpp
+++ b/mozilla/dom/src/base/nsGlobalWindow.cpp
@@ -5010,8 +5010,8 @@ nsGlobalWindow::GetFrames(nsIDOMWindow** aFrames)
   return NS_OK;
 }
 
-static nsGlobalWindow*
-CallerInnerWindow()
+nsGlobalWindow*
+nsGlobalWindow::CallerInnerWindow()
 {
   nsAXPCNativeCallContext *ncc;
   nsresult rv = nsContentUtils::XPConnect()->GetCurrentNativeCallContext(&ncc);
@@ -5041,6 +5041,8 @@ CallerInnerWindow()
   // raw pointer here and let the QI's addref be balanced by the nsCOMPtr
   // destructor's release.
   nsCOMPtr<nsPIDOMWindow> win = do_QueryWrappedNative(wrapper);
+  if (!win)
+    return GetCurrentInnerWindowInternal();
   return static_cast<nsGlobalWindow*>(win.get());
 }
 
diff --git a/mozilla/dom/src/base/nsGlobalWindow.h b/mozilla/dom/src/base/nsGlobalWindow.h
index f1a3e575938..8517d63b343 100644
--- a/mozilla/dom/src/base/nsGlobalWindow.h
+++ b/mozilla/dom/src/base/nsGlobalWindow.h
@@ -435,6 +435,7 @@ protected:
   void ClearControllers();
 
   void FreeInnerObjects(PRBool aClearScope);
+  nsGlobalWindow *CallerInnerWindow();
 
   nsresult SetNewDocument(nsIDocument *aDocument,
                           nsISupports *aState,