diff --git a/web/app/assets/javascripts/session.js b/web/app/assets/javascripts/session.js
index d0ec218d7..c6f8ae71c 100644
--- a/web/app/assets/javascripts/session.js
+++ b/web/app/assets/javascripts/session.js
@@ -841,7 +841,8 @@
             context._.each(mixers, function(mixer) {
               var mediaType = mixer.media_type;
 
-              if(mediaType == 'RecordingTrack') {
+              // mediaType == null is for backwards compat with older clients.  Can be removed soon
+              if(mediaType == null || mediaType == "" || mediaType == 'RecordingTrack') {
                 recordingTrackMixers.push(mixer)
               } else if(mediaType == 'PeerMediaTrack' || mediaType == 'BackingTrack') {
                 // BackingTrack