diff --git a/dom/media/MediaStreamTrack.cpp b/dom/media/MediaStreamTrack.cpp
index ae5af9b1f48e..f4fc249ec469 100644
--- a/dom/media/MediaStreamTrack.cpp
+++ b/dom/media/MediaStreamTrack.cpp
@@ -398,13 +398,6 @@ 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"));