--- a/dom/media/tests/mochitest/pc.js
+++ b/dom/media/tests/mochitest/pc.js
@@ -872,17 +872,20 @@ PeerConnectionWrapper.prototype = {
     ok(track.id, "track has id");
     ok(track.kind, "track has kind");
     ok(stream.id, "stream has id");
     this.expectedLocalTrackInfoById[track.id] = {
       type: track.kind,
       streamId: stream.id,
     };
 
-    this.ensureMediaElement(track, stream, "local");
+    // This will create one media element per track, which might not be how
+    // we set up things with the RTCPeerConnection. It's the only way
+    // we can ensure all sent tracks are flowing however.
+    this.ensureMediaElement(track, new MediaStream([track]), "local");
 
     return this.observedNegotiationNeeded;
   },
 
   /**
    * Callback when we get local media. Also an appropriate HTML media element
    * will be created, which may be obtained later with |getMediaElement|.
    *