diff --git a/packager/mpd/base/mpd_utils.cc b/packager/mpd/base/mpd_utils.cc
index 4840f2020d8..0f945f6538c 100644
--- a/packager/mpd/base/mpd_utils.cc
+++ b/packager/mpd/base/mpd_utils.cc
@@ -164,6 +164,8 @@ std::string GetAdaptationSetKey(const MediaInfo& media_info,
     key.append(GetBaseCodec(media_info));
 
     if (GetBaseCodec(media_info).find("dvh") == 0) {
+      // Transfer characteristics for Dolby Vision (dvh1 or dvhe) must be PQ
+      // irrespective of value present in SPS VUI.
       key.append(":");
       key.append(std::to_string(kTransferFunctionPQ));
     } else if (media_info.video_info().has_transfer_characteristics()) {
diff --git a/packager/mpd/base/period.cc b/packager/mpd/base/period.cc
index a2f2f99d9fe..0cb8273d03d 100644
--- a/packager/mpd/base/period.cc
+++ b/packager/mpd/base/period.cc
@@ -276,6 +276,8 @@ bool Period::SetNewAdaptationSetAttributes(
     // - Common CCIP values.
     // Dolby vision:
     // https://professionalsupport.dolby.com/s/article/How-to-signal-Dolby-Vision-in-MPEG-DASH
+    // Transfer characteristics for Dolby Vision (dvh1 or dvhe) must be PQ
+    // irrespective of value present in SPS VUI.
     if (new_adaptation_set->codec().find("dvh") == 0) {
       new_adaptation_set->set_transfer_characteristics(kTransferFunctionPQ);
     } else if (media_info.video_info().has_transfer_characteristics()) {