--- a/dom/media/mediasource/TrackBuffersManager.cpp
+++ b/dom/media/mediasource/TrackBuffersManager.cpp
@@ -2245,16 +2245,28 @@ TrackBuffersManager::GetSample(TrackInfo
 int32_t
 TrackBuffersManager::FindCurrentPosition(TrackInfo::TrackType aTrack,
                                          const TimeUnit& aFuzz)
 {
   MOZ_ASSERT(OnTaskQueue());
   auto& trackData = GetTracksData(aTrack);
   const TrackBuffer& track = GetTrackBuffer(aTrack);
 
+  // Perform an exact search first.
+  for (uint32_t i = 0; i < track.Length(); i++) {
+    const RefPtr<MediaRawData>& sample = track[i];
+    TimeInterval sampleInterval{
+      TimeUnit::FromMicroseconds(sample->mTimecode),
+      TimeUnit::FromMicroseconds(sample->mTimecode + sample->mDuration)};
+
+    if (sampleInterval.ContainsStrict(trackData.mNextSampleTimecode)) {
+      return i;
+    }
+  }
+
   for (uint32_t i = 0; i < track.Length(); i++) {
     const RefPtr<MediaRawData>& sample = track[i];
     TimeInterval sampleInterval{
       TimeUnit::FromMicroseconds(sample->mTimecode),
       TimeUnit::FromMicroseconds(sample->mTimecode + sample->mDuration),
       aFuzz};
 
     if (sampleInterval.ContainsWithStrictEnd(trackData.mNextSampleTimecode)) {