--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -590,17 +590,19 @@ public:
     if (mMaster->mPlayState != MediaDecoder::PLAY_STATE_PLAYING &&
         mMaster->IsPlaying()) {
       // We're playing, but the element/decoder is in paused state. Stop
       // playing!
       mMaster->StopPlayback();
     }
 
     // Start playback if necessary so that the clock can be properly queried.
-    mMaster->MaybeStartPlayback();
+    if (!mMaster->mIsPrerolling) {
+      mMaster->MaybeStartPlayback();
+    }
 
     mMaster->UpdatePlaybackPositionPeriodically();
 
     MOZ_ASSERT(!mMaster->IsPlaying() ||
                mMaster->IsStateMachineScheduled(),
                "Must have timer scheduled");
 
     mMaster->MaybeStartBuffering();
@@ -1772,20 +1774,20 @@ void MediaDecoderStateMachine::MaybeStar
              mState == DECODER_STATE_COMPLETED);
 
   if (IsPlaying()) {
     // Logging this case is really spammy - don't do it.
     return;
   }
 
   bool playStatePermits = mPlayState == MediaDecoder::PLAY_STATE_PLAYING;
-  if (!playStatePermits || mIsPrerolling || mAudioOffloading) {
+  if (!playStatePermits || mAudioOffloading) {
     DECODER_LOG("Not starting playback [playStatePermits: %d, "
-                "mIsPrerolling: %d, mAudioOffloading: %d]",
-                playStatePermits, mIsPrerolling, mAudioOffloading);
+                "mAudioOffloading: %d]",
+                playStatePermits, mAudioOffloading);
     return;
   }
 
   DECODER_LOG("MaybeStartPlayback() starting playback");
   mOnPlaybackEvent.Notify(MediaEventType::PlaybackStarted);
   StartMediaSink();
 
   if (!IsPlaying()) {