--- a/dom/media/flac/FlacFrameParser.cpp
+++ b/dom/media/flac/FlacFrameParser.cpp
@@ -127,17 +127,17 @@ FlacFrameParser::DecodeHeaderBlock(const
       uint32_t sampleRate = (blob >> 44) & BITMASK(20);
       if (!sampleRate) {
         return false;
       }
       uint32_t numChannels = ((blob >> 41) & BITMASK(3)) + 1;
       if (numChannels > FLAC_MAX_CHANNELS) {
         return false;
       }
-      uint32_t bps = ((blob >> 38) & BITMASK(5)) + 1;
+      uint32_t bps = ((blob >> 36) & BITMASK(5)) + 1;
       if (bps > 24) {
         return false;
       }
       mNumFrames = blob & BITMASK(36);
 
       mInfo.mMimeType = "audio/flac";
       mInfo.mRate = sampleRate;
       mInfo.mChannels = numChannels;