--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -1387,18 +1387,18 @@ void MediaDecoderStateMachine::StartDeco
   mDecodeStartTime = TimeStamp::Now();
 
   CheckIfDecodeComplete();
   if (mState == DECODER_STATE_COMPLETED) {
     return;
   }
 
   // Reset other state to pristine values before starting decode.
-  mIsAudioPrerolling = !DonePrerollingAudio();
-  mIsVideoPrerolling = !DonePrerollingVideo();
+  mIsAudioPrerolling = !DonePrerollingAudio() && !mAudioWaitRequest.Exists();
+  mIsVideoPrerolling = !DonePrerollingVideo() && !mVideoWaitRequest.Exists();
 
   // Ensure that we've got tasks enqueued to decode data if we need to.
   DispatchDecodeTasksIfNeeded();
 
   ScheduleStateMachine();
 }
 
 void MediaDecoderStateMachine::PlayStateChanged()