diff --git a/lib/transports/polling-xhr.js b/lib/transports/polling-xhr.js
index cc16d9dc9..8aeef5cd9 100755
--- a/lib/transports/polling-xhr.js
+++ b/lib/transports/polling-xhr.js
@@ -255,7 +255,7 @@ Request.prototype.create = function () {
           // make sure the `error` event handler that's user-set
           // does not throw in the same tick and gets caught here
           setTimeout(function () {
-            self.onError(xhr.status);
+            self.onError(typeof xhr.status === 'number' ? xhr.status : 0);
           }, 0);
         }
       };