--- a/dom/push/test/xpcshell/head-http2.js
+++ b/dom/push/test/xpcshell/head-http2.js
@@ -39,18 +39,17 @@ CertOverrideListener.prototype = {
               getService(Ci.nsICertOverrideService);
     cos.rememberValidityOverride(this.host, this.port, cert, this.bits, false);
     dump("Certificate Override in place\n");
     return true;
   },
 };
 
 function addCertOverride(host, port, bits) {
-  var req = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
-            .createInstance(Ci.nsIXMLHttpRequest);
+  var req = new XMLHttpRequest();
   try {
     var url;
     if (port && (port > 0) && (port !== 443)) {
       url = "https://" + host + ":" + port + "/";
     } else {
       url = "https://" + host + "/";
     }
     req.open("GET", url, false);