--- a/toolkit/components/telemetry/TelemetrySend.jsm
+++ b/toolkit/components/telemetry/TelemetrySend.jsm
@@ -902,16 +902,19 @@ var TelemetrySendImpl = {
 
     request.open("POST", url, true);
     request.overrideMimeType("text/plain");
     request.setRequestHeader("Content-Type", "application/json; charset=UTF-8");
     request.setRequestHeader("Date", Policy.now().toUTCString());
 
     this._pendingPingRequests.set(id, request);
 
+    // Prevent the request channel from running though URLClassifier (bug 1296802)
+    request.channel.loadFlags &= ~Ci.nsIChannel.LOAD_CLASSIFY_URI;
+
     let startTime = new Date();
     let deferred = PromiseUtils.defer();
 
     let onRequestFinished = (success, event) => {
       let onCompletion = () => {
         if (success) {
           deferred.resolve();
         } else {