--- a/dom/media/tests/mochitest/pc.js
+++ b/dom/media/tests/mochitest/pc.js
@@ -1430,18 +1430,19 @@ PeerConnectionWrapper.prototype = {
       info("Track " + track.id + " has " + nrPackets + " " +
            rtp.type + " RTP packets.");
       return nrPackets > 0;
     };
 
     info("Checking RTP packet flow for track " + track.id);
 
     var retry = (delay) => this._pc.getStats(track)
-      .then(stats => hasFlow(stats)? ok(true, "RTP flowing for track " + track.id) :
-            wait(delay).then(retry(1000)));
+      .then(stats => hasFlow(stats)
+          ? ok(true, "RTP flowing for track " + track.id)
+          : wait(delay).then(() => retry(1000)));
     return retry(200);
   },
 
   /**
    * Wait for presence of video flow on all media elements and rtp flow on
    * all sending and receiving track involved in this test.
    *
    * @returns {Promise}