diff --git a/api/test/video_quality_test_fixture.h b/api/test/video_quality_test_fixture.h
index 0aa23b17bf..b45faef286 100644
--- a/api/test/video_quality_test_fixture.h
+++ b/api/test/video_quality_test_fixture.h
@@ -37,6 +37,7 @@ class VideoQualityTestFixtureInterface {
     struct CallConfig {
       bool send_side_bwe = false;
       bool generic_descriptor = false;
+      bool dependency_descriptor = false;
       BitrateConstraints call_bitrate_config;
       int num_thumbnails = 0;
       // Indicates if secondary_(video|ss|screenshare) structures are used.
diff --git a/video/video_loopback.cc b/video/video_loopback.cc
index 7762d9653d..ba0a0e5745 100644
--- a/video/video_loopback.cc
+++ b/video/video_loopback.cc
@@ -171,6 +171,8 @@ ABSL_FLAG(bool, send_side_bwe, true, "Use send-side bandwidth estimation");
 
 ABSL_FLAG(bool, generic_descriptor, false, "Use the generic frame descriptor.");
 
+ABSL_FLAG(bool, dependency_descriptor, false, "Use the dependency descriptor.");
+
 ABSL_FLAG(bool, allow_reordering, false, "Allow packet reordering to occur");
 
 ABSL_FLAG(bool, use_ulpfec, false, "Use RED+ULPFEC forward error correction.");
@@ -378,6 +380,8 @@ void Loopback() {
   VideoQualityTest::Params params;
   params.call.send_side_bwe = absl::GetFlag(FLAGS_send_side_bwe);
   params.call.generic_descriptor = absl::GetFlag(FLAGS_generic_descriptor);
+  params.call.dependency_descriptor =
+      absl::GetFlag(FLAGS_dependency_descriptor);
   params.call.call_bitrate_config = call_bitrate_config;
 
   params.video[0].enabled = absl::GetFlag(FLAGS_video);
diff --git a/video/video_quality_test.cc b/video/video_quality_test.cc
index 21dfaa8ae8..b32343fb28 100644
--- a/video/video_quality_test.cc
+++ b/video/video_quality_test.cc
@@ -710,7 +710,9 @@ void VideoQualityTest::SetupVideo(Transport* send_transport,
   std::string generic_codec_name;
   webrtc::VideoEncoder::EncoderInfo encoder_info;
   for (size_t video_idx = 0; video_idx < num_video_streams_; ++video_idx) {
-    video_send_configs_.push_back(VideoSendStream::Config(send_transport));
+    VideoSendStream::Config config(send_transport);
+    config.rtp.extmap_allow_mixed = true;
+    video_send_configs_.push_back(std::move(config));
     video_encoder_configs_.push_back(VideoEncoderConfig());
     num_video_substreams = params_.ss[video_idx].streams.size();
     RTC_CHECK_GT(num_video_substreams, 0);
@@ -769,6 +771,12 @@ void VideoQualityTest::SetupVideo(Transport* send_transport,
           kGenericFrameDescriptorExtensionId00);
     }
 
+    if (params_.call.dependency_descriptor) {
+      video_send_configs_[video_idx].rtp.extensions.emplace_back(
+          RtpExtension::kDependencyDescriptorUri,
+          kRtpExtensionGenericFrameDescriptor02);
+    }
+
     video_send_configs_[video_idx].rtp.extensions.emplace_back(
         RtpExtension::kVideoContentTypeUri, kVideoContentTypeExtensionId);
     video_send_configs_[video_idx].rtp.extensions.emplace_back(