diff --git a/dom/media/MediaStreamTrack.cpp b/dom/media/MediaStreamTrack.cpp
index 2c0d2ce2bb48..e2603d9fa020 100644
--- a/dom/media/MediaStreamTrack.cpp
+++ b/dom/media/MediaStreamTrack.cpp
@@ -414,13 +414,6 @@ MediaStreamTrack::NotifyEnded()
 
   LOG(LogLevel::Info, ("MediaStreamTrack %p ended", this));
 
-  if (!mSource) {
-    MOZ_ASSERT(false);
-    return;
-  }
-
-  mSource->UnregisterSink(this);
-
   mReadyState = MediaStreamTrackState::Ended;
 
   DispatchTrustedEvent(NS_LITERAL_STRING("ended"));