diff --git a/dom/media/MediaDecoderStateMachine.cpp b/dom/media/MediaDecoderStateMachine.cpp
index 25960a9ef457..5b688778bf39 100644
--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -814,20 +814,20 @@ private:
 
     TimeDuration decodeTime = TimeStamp::Now() - aDecodeStart;
     int64_t adjustedTime = THRESHOLD_FACTOR * DurationToUsecs(decodeTime);
-    if (adjustedTime > mMaster->mLowAudioThresholdUsecs
+    if (adjustedTime > mMaster->mLowAudioThresholdUsecs.ToMicroseconds()
         && !mMaster->HasLowBufferedData())
     {
-      mMaster->mLowAudioThresholdUsecs =
-        std::min(adjustedTime, mMaster->mAmpleAudioThresholdUsecs);
+      mMaster->mLowAudioThresholdUsecs = TimeUnit::FromMicroseconds(
+        std::min(adjustedTime, mMaster->mAmpleAudioThresholdUsecs));
 
       mMaster->mAmpleAudioThresholdUsecs =
-        std::max(THRESHOLD_FACTOR * mMaster->mLowAudioThresholdUsecs,
+        std::max(THRESHOLD_FACTOR * mMaster->mLowAudioThresholdUsecs.ToMicroseconds(),
                  mMaster->mAmpleAudioThresholdUsecs);
 
       SLOG("Slow video decode, set "
            "mLowAudioThresholdUsecs=%" PRId64
            " mAmpleAudioThresholdUsecs=%" PRId64,
-           mMaster->mLowAudioThresholdUsecs,
+           mMaster->mLowAudioThresholdUsecs.ToMicroseconds(),
            mMaster->mAmpleAudioThresholdUsecs);
     }
   }
@@ -2299,7 +2299,7 @@ DecodingState::NeedToSkipToNextKeyframe()
     !Reader()->IsAsync()
     && mMaster->IsAudioDecoding()
     && (mMaster->GetDecodedAudioDuration()
-        < mMaster->mLowAudioThresholdUsecs * mMaster->mPlaybackRate);
+        < mMaster->mLowAudioThresholdUsecs.ToMicroseconds() * mMaster->mPlaybackRate);
   bool isLowOnDecodedVideo =
     (mMaster->GetClock() - mMaster->mDecodedVideoEndTime)
     * mMaster->mPlaybackRate
@@ -2594,7 +2594,7 @@ MediaDecoderStateMachine::MediaDecoderStateMachine(MediaDecoder* aDecoder,
   mDecodedAudioEndTime(0),
   mDecodedVideoEndTime(0),
   mPlaybackRate(1.0),
-  mLowAudioThresholdUsecs(detail::LOW_AUDIO_USECS.ToMicroseconds()),
+  mLowAudioThresholdUsecs(detail::LOW_AUDIO_USECS),
   mAmpleAudioThresholdUsecs(detail::AMPLE_AUDIO_USECS),
   mAudioCaptured(false),
   mMinimizePreroll(aDecoder->GetMinimizePreroll()),
diff --git a/dom/media/MediaDecoderStateMachine.h b/dom/media/MediaDecoderStateMachine.h
index 3c60a2b86ec1..846c699c1b5b 100644
--- a/dom/media/MediaDecoderStateMachine.h
+++ b/dom/media/MediaDecoderStateMachine.h
@@ -583,7 +583,7 @@ private:
   // decode video frames, in order to reduce the chance of audio underruns.
   // Note that we don't ever reset this threshold, it only ever grows as
   // we detect that the decode can't keep up with rendering.
-  int64_t mLowAudioThresholdUsecs;
+  media::TimeUnit mLowAudioThresholdUsecs;
 
   // Our "ample" audio threshold. Once we've this much audio decoded, we
   // pause decoding. If we increase mLowAudioThresholdUsecs, we'll also