--- a/dom/media/TrackUnionStream.cpp
+++ b/dom/media/TrackUnionStream.cpp
@@ -53,16 +53,20 @@ TrackUnionStream::TrackUnionStream() :
 
   void TrackUnionStream::RemoveInput(MediaInputPort* aPort)
   {
     STREAM_LOG(LogLevel::Debug, ("TrackUnionStream %p removing input %p", this, aPort));
     for (int32_t i = mTrackMap.Length() - 1; i >= 0; --i) {
       if (mTrackMap[i].mInputPort == aPort) {
         STREAM_LOG(LogLevel::Debug, ("TrackUnionStream %p removing trackmap entry %d", this, i));
         EndTrack(i);
+        for (auto listener : mTrackMap[i].mOwnedDirectListeners) {
+          // Remove listeners while the entry still exists.
+          RemoveDirectTrackListenerImpl(listener, mTrackMap[i].mOutputTrackID);
+        }
         mTrackMap.RemoveElementAt(i);
       }
     }
     ProcessedMediaStream::RemoveInput(aPort);
   }
   void TrackUnionStream::ProcessInput(GraphTime aFrom, GraphTime aTo, uint32_t aFlags)
   {
     if (IsFinishedOnGraphThread()) {
@@ -125,16 +129,20 @@ TrackUnionStream::TrackUnionStream() :
     }
     for (int32_t i = mTrackMap.Length() - 1; i >= 0; --i) {
       if (mappedTracksFinished[i]) {
         EndTrack(i);
       } else {
         allFinished = false;
       }
       if (!mappedTracksWithMatchingInputTracks[i]) {
+        for (auto listener : mTrackMap[i].mOwnedDirectListeners) {
+          // Remove listeners while the entry still exists.
+          RemoveDirectTrackListenerImpl(listener, mTrackMap[i].mOutputTrackID);
+        }
         mTrackMap.RemoveElementAt(i);
       }
     }
     if (allFinished && mAutofinish && (aFlags & ALLOW_FINISH)) {
       // All streams have finished and won't add any more tracks, and
       // all our tracks have actually finished and been removed from our map,
       // so we're finished now.
       FinishOnGraphThread();