--- a/dom/media/webaudio/MediaStreamAudioSourceNode.cpp
+++ b/dom/media/webaudio/MediaStreamAudioSourceNode.cpp
@@ -128,18 +128,22 @@ MediaStreamAudioSourceNode::AttachToFirs
   aMediaStream->GetAudioTracks(tracks);
 
   for (const RefPtr<AudioStreamTrack>& track : tracks) {
     if (track->Ended()) {
       continue;
     }
 
     AttachToTrack(track);
+    MarkActive();
     return;
   }
+
+  // There was no track available. We'll allow the node to be garbage collected.
+  MarkInactive();
 }
 
 void
 MediaStreamAudioSourceNode::NotifyTrackAdded(const RefPtr<MediaStreamTrack>& aTrack)
 {
   if (mInputTrack) {
     return;
   }