--- a/dom/media/MediaFormatReader.cpp
+++ b/dom/media/MediaFormatReader.cpp
@@ -1109,18 +1109,20 @@ MediaFormatReader::Update(TrackType aTra
             !decoder.mNextStreamSourceID) {
           // We have completed draining the decoder following WaitingForData.
           // Set up the internal seek machinery to be able to resume from the
           // last sample decoded.
           LOG("Seeking to last sample time: %lld",
               decoder.mLastSampleTime.ref().ToMicroseconds());
           InternalSeek(aTrack, InternalSeekTarget(decoder.mLastSampleTime.ref(), true));
         }
-        LOG("Rejecting %s promise: WAITING_FOR_DATA", TrackTypeToStr(aTrack));
-        decoder.RejectPromise(WAITING_FOR_DATA, __func__);
+        if (!decoder.mReceivedNewData) {
+          LOG("Rejecting %s promise: WAITING_FOR_DATA", TrackTypeToStr(aTrack));
+          decoder.RejectPromise(WAITING_FOR_DATA, __func__);
+        }
       }
       // Now that draining has completed, we check if we have received
       // new data again as the result may now be different from the earlier
       // run.
       if (UpdateReceivedNewData(aTrack)) {
         LOGV("Nothing more to do");
         return;
       }