diff --git a/layout/xul/nsMenuBarListener.cpp b/layout/xul/nsMenuBarListener.cpp
index 35a33ba0661f..0fce497b80b1 100644
--- a/layout/xul/nsMenuBarListener.cpp
+++ b/layout/xul/nsMenuBarListener.cpp
@@ -211,7 +211,8 @@ nsMenuBarListener::KeyPress(nsIDOMEvent* aKeyEvent)
     // the mozaccesskeynotfound event before handling accesskeys.
     WidgetKeyboardEvent* nativeKeyEvent =
       aKeyEvent->WidgetEventPtr()->AsKeyboardEvent();
-    if (nativeKeyEvent && nativeKeyEvent->mAccessKeyForwardedToChild) {
+    if (!nativeKeyEvent ||
+        (nativeKeyEvent && nativeKeyEvent->mAccessKeyForwardedToChild)) {
       return NS_OK;
     }