--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -2542,16 +2542,17 @@ ShutdownState::Enter()
   master->mNextPlayState.DisconnectIfConnected();
   master->mVolume.DisconnectIfConnected();
   master->mPreservesPitch.DisconnectIfConnected();
   master->mSameOriginMedia.DisconnectIfConnected();
   master->mMediaPrincipalHandle.DisconnectIfConnected();
   master->mPlaybackBytesPerSecond.DisconnectIfConnected();
   master->mPlaybackRateReliable.DisconnectIfConnected();
   master->mDecoderPosition.DisconnectIfConnected();
+  master->mVideoDecodeMode.DisconnectIfConnected();
 
   master->mDuration.DisconnectAll();
   master->mIsShutdown.DisconnectAll();
   master->mNextFrameStatus.DisconnectAll();
   master->mCurrentPosition.DisconnectAll();
   master->mPlaybackOffset.DisconnectAll();
   master->mIsAudioDataAudible.DisconnectAll();
 
@@ -2679,16 +2680,17 @@ MediaDecoderStateMachine::Initialization
                       &MediaDecoderStateMachine::RecomputeDuration);
   mWatchManager.Watch(mExplicitDuration,
                       &MediaDecoderStateMachine::RecomputeDuration);
   mWatchManager.Watch(mObservedDuration,
                       &MediaDecoderStateMachine::RecomputeDuration);
   mWatchManager.Watch(mPlayState, &MediaDecoderStateMachine::PlayStateChanged);
 
   if (MediaPrefs::MDSMSuspendBackgroundVideoEnabled()) {
+    mVideoDecodeMode.Connect(aDecoder->CanonicalVideoDecodeMode());
     mWatchManager.Watch(mVideoDecodeMode,
                         &MediaDecoderStateMachine::VideoDecodeModeChanged);
   }
 
   MOZ_ASSERT(!mStateObj);
   auto* s = new DecodeMetadataState(this);
   mStateObj.reset(s);
   s->Enter();