--- a/dom/media/MediaFormatReader.cpp
+++ b/dom/media/MediaFormatReader.cpp
@@ -577,17 +577,17 @@ MediaFormatReader::OnDemuxFailed(TrackTy
       NotifyError(aTrack);
       break;
     case DemuxerFailureReason::WAITING_FOR_DATA:
       if (!decoder.mWaitingForData) {
         decoder.mNeedDraining = true;
       }
       NotifyWaitingForData(aTrack);
       break;
-    case DemuxerFailureReason::CANCELED: MOZ_FALLTHROUGH;
+    case DemuxerFailureReason::CANCELED:
     case DemuxerFailureReason::SHUTDOWN:
       if (decoder.HasPromise()) {
         decoder.RejectPromise(CANCELED, __func__);
       }
       break;
     default:
       MOZ_ASSERT(false);
       break;
@@ -1062,17 +1062,17 @@ MediaFormatReader::InternalSeek(TrackTyp
                       switch (aResult) {
                         case DemuxerFailureReason::WAITING_FOR_DATA:
                           self->NotifyWaitingForData(aTrack);
                           break;
                         case DemuxerFailureReason::END_OF_STREAM:
                           decoder.mTimeThreshold.reset();
                           self->NotifyEndOfStream(aTrack);
                           break;
-                        case DemuxerFailureReason::CANCELED: MOZ_FALLTHROUGH;
+                        case DemuxerFailureReason::CANCELED:
                         case DemuxerFailureReason::SHUTDOWN:
                           decoder.mTimeThreshold.reset();
                           break;
                         default:
                           decoder.mTimeThreshold.reset();
                           self->NotifyError(aTrack);
                           break;
                       }
@@ -1551,26 +1551,26 @@ MediaFormatReader::OnVideoSkipCompleted(
 void
 MediaFormatReader::OnVideoSkipFailed(MediaTrackDemuxer::SkipFailureHolder aFailure)
 {
   MOZ_ASSERT(OnTaskQueue());
   LOG("Skipping failed, skipped %u frames", aFailure.mSkipped);
   mSkipRequest.Complete();
 
   switch (aFailure.mFailure) {
-    case DemuxerFailureReason::END_OF_STREAM: MOZ_FALLTHROUGH;
+    case DemuxerFailureReason::END_OF_STREAM:
     case DemuxerFailureReason::WAITING_FOR_DATA:
       // Some frames may have been output by the decoder since we initiated the
       // videoskip process and we know they would be late.
       DropDecodedSamples(TrackInfo::kVideoTrack);
       // We can't complete the skip operation, will just service a video frame
       // normally.
       NotifyDecodingRequested(TrackInfo::kVideoTrack);
       break;
-    case DemuxerFailureReason::CANCELED: MOZ_FALLTHROUGH;
+    case DemuxerFailureReason::CANCELED:
     case DemuxerFailureReason::SHUTDOWN:
       if (mVideo.HasPromise()) {
         mVideo.RejectPromise(CANCELED, __func__);
       }
       break;
     default:
       NotifyError(TrackType::kVideoTrack);
       break;