diff --git a/src/r7insight.js b/src/r7insight.js
index cccea90..1b6e6a5 100644
--- a/src/r7insight.js
+++ b/src/r7insight.js
@@ -230,7 +230,7 @@
             var request = _getAjaxObject();
 
             if (_shouldCall) {
-                if (request.constructor instanceof XMLHttpRequest) {
+                if (request instanceof XMLHttpRequest) {
                     // Currently we don't support fine-grained error
                     // handling in older versions of IE
                     request.onreadystatechange = function() {