--- a/extensions/pref/autoconfig/src/nsAutoConfig.cpp
+++ b/extensions/pref/autoconfig/src/nsAutoConfig.cpp
@@ -131,18 +131,18 @@ nsAutoConfig::OnStopRequest(nsIRequest *
                                        static_cast<uint32_t>(aStatus)));
         return readOfflineFile();
     }
 
     // Checking for the http response, if failure go read the failover file.
     nsCOMPtr<nsIHttpChannel> pHTTPCon(do_QueryInterface(request));
     if (pHTTPCon) {
         uint32_t httpStatus;
-        pHTTPCon->GetResponseStatus(&httpStatus);
-        if (httpStatus != 200) 
+        rv = pHTTPCon->GetResponseStatus(&httpStatus);
+        if (NS_FAILED(rv) || httpStatus != 200)
         {
             MOZ_LOG(MCD, LogLevel::Debug, ("mcd http request failed with status %x\n", httpStatus));
             return readOfflineFile();
         }
     }
     
     // Send the autoconfig.jsc to javascript engine.