--- a/dom/media/mediasource/TrackBuffersManager.cpp
+++ b/dom/media/mediasource/TrackBuffersManager.cpp
@@ -1685,19 +1685,21 @@ TrackBuffersManager::InsertFrames(TrackB
   data.InsertElementsAt(trackBuffer.mNextInsertionIndex.ref(), aSamples);
   trackBuffer.mNextInsertionIndex.ref() += aSamples.Length();
 
   // Update our buffered range with new sample interval.
   trackBuffer.mBufferedRanges += aIntervals;
   // We allow a fuzz factor in our interval of half a frame length,
   // as fuzz is +/- value, giving an effective leeway of a full frame
   // length.
-  TimeIntervals range(aIntervals);
-  range.SetFuzz(trackBuffer.mLongestFrameDuration.ref() / 2);
-  trackBuffer.mSanitizedBufferedRanges += range;
+  if (aIntervals.Length()) {
+    TimeIntervals range(aIntervals);
+    range.SetFuzz(trackBuffer.mLongestFrameDuration.ref() / 2);
+    trackBuffer.mSanitizedBufferedRanges += range;
+  }
 }
 
 void
 TrackBuffersManager::RemoveFrames(const TimeIntervals& aIntervals,
                                   TrackData& aTrackData,
                                   uint32_t aStartIndex)
 {
   TrackBuffer& data = aTrackData.mBuffers.LastElement();