--- a/dom/media/MediaFormatReader.cpp
+++ b/dom/media/MediaFormatReader.cpp
@@ -1076,25 +1076,21 @@ MediaFormatReader::Shutdown()
   }
 
   mShutdownPromisePool->Track(mDemuxer->Shutdown());
   mDemuxer = nullptr;
 
   mCompositorUpdatedListener.DisconnectIfExists();
   mOnTrackWaitingForKeyListener.Disconnect();
 
-  RefPtr<ShutdownPromise> p = mShutdownPromise.Ensure(__func__);
-  mShutdownPromisePool->Shutdown()
+  mShutdown = true;
+  return mShutdownPromisePool->Shutdown()
     ->Then(OwnerThread(), __func__, this,
            &MediaFormatReader::TearDownDecoders,
            &MediaFormatReader::TearDownDecoders);
-
-  mShutdown = true;
-
-  return p;
 }
 
 RefPtr<ShutdownPromise>
 MediaFormatReader::ShutdownDecoderWithPromise(TrackType aTrack)
 {
   LOGV("%s", TrackTypeToStr(aTrack));
 
   auto& decoder = GetDecoderData(aTrack);
@@ -1137,17 +1133,17 @@ MediaFormatReader::ShutdownDecoder(Track
   }
   if (!decoder.mShutdownPromise.IsEmpty()) {
     LOGV("Shutdown already in progress");
     return;
   }
   Unused << ShutdownDecoderWithPromise(aTrack);
 }
 
-void
+RefPtr<ShutdownPromise>
 MediaFormatReader::TearDownDecoders()
 {
   if (mAudio.mTaskQueue) {
     mAudio.mTaskQueue->BeginShutdown();
     mAudio.mTaskQueue->AwaitShutdownAndIdle();
     mAudio.mTaskQueue = nullptr;
   }
   if (mVideo.mTaskQueue) {
@@ -1155,22 +1151,17 @@ MediaFormatReader::TearDownDecoders()
     mVideo.mTaskQueue->AwaitShutdownAndIdle();
     mVideo.mTaskQueue = nullptr;
   }
 
   mDecoderFactory = nullptr;
   mPlatform = nullptr;
   mVideoFrameContainer = nullptr;
 
-  if (mShutdownPromise.IsEmpty()) {
-    return;
-  }
-
-  MediaDecoderReader::Shutdown();
-  mShutdownPromise.Resolve(true, __func__);
+  return MediaDecoderReader::Shutdown();
 }
 
 void
 MediaFormatReader::InitLayersBackendType()
 {
   // Extract the layer manager backend type so that platform decoders
   // can determine whether it's worthwhile using hardware accelerated
   // video decoding.

--- a/dom/media/MediaFormatReader.h
+++ b/dom/media/MediaFormatReader.h
@@ -590,15 +590,14 @@ private:
 
   UniquePtr<MetadataTags> mTags;
 
   // A flag indicating if the start time is known or not.
   bool mHasStartTime = false;
 
   void ShutdownDecoder(TrackType aTrack);
   RefPtr<ShutdownPromise> ShutdownDecoderWithPromise(TrackType aTrack);
-  void TearDownDecoders();
-  MozPromiseHolder<ShutdownPromise> mShutdownPromise;
+  RefPtr<ShutdownPromise> TearDownDecoders();
 };
 
 } // namespace mozilla
 
 #endif