diff --git a/mozilla/dom/src/base/nsDOMClassInfo.cpp b/mozilla/dom/src/base/nsDOMClassInfo.cpp
index 67eac4bb90d..adaf6a2e8b0 100644
--- a/mozilla/dom/src/base/nsDOMClassInfo.cpp
+++ b/mozilla/dom/src/base/nsDOMClassInfo.cpp
@@ -6888,6 +6888,13 @@ nsEventReceiverSH::AddEventListenerHelper(JSContext *cx, JSObject *obj,
     return JS_FALSE;
   }
 
+  rv = sXPConnect->GetWrappedNativeOfJSObject(cx, obj, getter_AddRefs(wrapper));
+  if (NS_FAILED(rv)) {
+    nsDOMClassInfo::ThrowJSException(cx, rv);
+
+    return JS_FALSE;
+  }
+
   // Check that the caller has permission to call obj's addEventListener.
   if (NS_FAILED(sSecMan->CheckPropertyAccess(cx, obj,
                                              JS_GET_CLASS(cx, obj)->name,
diff --git a/mozilla/js/src/xpconnect/src/xpccomponents.cpp b/mozilla/js/src/xpconnect/src/xpccomponents.cpp
index 9827a851b64..71e0867199b 100644
--- a/mozilla/js/src/xpconnect/src/xpccomponents.cpp
+++ b/mozilla/js/src/xpconnect/src/xpccomponents.cpp
@@ -2803,12 +2803,16 @@ nsXPCComponents_Utils::LookupMethod()
         return NS_ERROR_XPC_BAD_CONVERT_JS;
 
     JSObject* obj = JSVAL_TO_OBJECT(argv[0]);
-    XPCWrappedNative *wn =
-        XPCWrappedNative::GetWrappedNativeOfJSObject(cx, obj);
-    if(!wn)
-        return NS_ERROR_XPC_BAD_CONVERT_JS;
 
-    obj = wn->GetFlatJSObject();
+    {
+        XPCWrappedNative *wn =
+            XPCWrappedNative::GetWrappedNativeOfJSObject(cx, obj);
+        if(!wn)
+            return NS_ERROR_XPC_BAD_CONVERT_JS;
+
+        obj = wn->GetFlatJSObject();
+    }
+
     OBJ_TO_INNER_OBJECT(cx, obj);
     if(!obj)
         return NS_ERROR_XPC_BAD_CONVERT_JS;