diff --git a/dom/media/fmp4/MP4Decoder.cpp b/dom/media/fmp4/MP4Decoder.cpp
index fd40aea86b..0bdbccd59e 100644
--- a/dom/media/fmp4/MP4Decoder.cpp
+++ b/dom/media/fmp4/MP4Decoder.cpp
@@ -143,9 +143,16 @@ MP4Decoder::CanHandleMediaType(const MediaContentType& aType,
         continue;
       }
       if (IsVP9CodecString(codec)) {
-        trackInfos.AppendElement(
-          CreateTrackInfoWithMIMETypeAndContainerTypeExtraParameters(
-            NS_LITERAL_CSTRING("video/vp9"), aType));
+        auto trackInfo =
+          CreateTrackInfoWithMIMETypeAndContentTypeExtraParameters(
+            NS_LITERAL_CSTRING("video/vp9"), aType);
+        uint8_t profile = 0;
+        uint8_t level = 0;
+        uint8_t bitDepth = 0;
+        if (ExtractVPXCodecDetails(codec, profile, level, bitDepth)) {
+          trackInfo->GetAsVideoInfo()->mBitDepth = bitDepth;
+        }
+        trackInfos.AppendElement(Move(trackInfo));
         continue;
       }
 #ifdef MOZ_AV1