--- a/dom/media/MediaFormatReader.cpp
+++ b/dom/media/MediaFormatReader.cpp
@@ -789,17 +789,17 @@ MediaFormatReader::UpdateReceivedNewData
     // We do not want to clear mWaitingForData or mDemuxEOS while
     // a drain is in progress in order to properly complete the operation.
     return false;
   }
 
   bool hasLastEnd;
   media::TimeUnit lastEnd = decoder.mTimeRanges.GetEnd(&hasLastEnd);
   if (hasLastEnd) {
-    if (decoder.mLastTimeRangesEnd && decoder.mLastTimeRangesEnd.ref() > lastEnd) {
+    if (decoder.mLastTimeRangesEnd && decoder.mLastTimeRangesEnd.ref() < lastEnd) {
       // New data was added after our previous end, we can clear the EOS flag.
       decoder.mDemuxEOS = false;
     }
     decoder.mLastTimeRangesEnd = Some(lastEnd);
   }
 
   decoder.mReceivedNewData = false;
   if (decoder.mTimeThreshold) {