diff --git a/webrtc/media/engine/internalencoderfactory.cc b/webrtc/media/engine/internalencoderfactory.cc
index 544070fc4c..a8d4f2d2c2 100644
--- a/webrtc/media/engine/internalencoderfactory.cc
+++ b/webrtc/media/engine/internalencoderfactory.cc
@@ -23,11 +23,12 @@ namespace {
 
 // If this field trial is enabled, the "flexfec-03" codec will be advertised
 // as being supported by the InternalEncoderFactory. This means that
-// "flexfec-03" will appear in the default local SDP, and we therefore need to
-// be ready to receive FlexFEC packets from the remote.
+// "flexfec-03" will appear in the default SDP offer, and we therefore need to
+// be ready to receive FlexFEC packets from the remote. It also means that
+// FlexFEC SSRCs will be generated by MediaSession and added as "a=ssrc:" and
+// "a=ssrc-group:" lines in the local SDP.
 bool IsFlexfecAdvertisedFieldTrialEnabled() {
-  return webrtc::field_trial::FindFullName("WebRTC-FlexFEC-03-Advertised") ==
-         "Enabled";
+  return webrtc::field_trial::IsEnabled("WebRTC-FlexFEC-03-Advertised");
 }
 
 }  // namespace
diff --git a/webrtc/media/engine/webrtcvideoengine2.cc b/webrtc/media/engine/webrtcvideoengine2.cc
index 7eb150bb65..65833873f6 100644
--- a/webrtc/media/engine/webrtcvideoengine2.cc
+++ b/webrtc/media/engine/webrtcvideoengine2.cc
@@ -43,10 +43,12 @@ using DegradationPreference = webrtc::VideoSendStream::DegradationPreference;
 namespace cricket {
 namespace {
 // If this field trial is enabled, we will enable sending FlexFEC and disable
-// sending ULPFEC whenever the former has been negotiated. Receiving FlexFEC
-// is enabled whenever FlexFEC has been negotiated.
+// sending ULPFEC whenever the former has been negotiated.
+// FlexFEC can only be negotiated when the "flexfec-03" SDP codec is enabled,
+// which is done by enabling the "WebRTC-FlexFEC-03-Advertised" field trial; see
+// internalencoderfactory.cc.
 bool IsFlexfecFieldTrialEnabled() {
-  return webrtc::field_trial::FindFullName("WebRTC-FlexFEC-03") == "Enabled";
+  return webrtc::field_trial::IsEnabled("WebRTC-FlexFEC-03");
 }
 
 // If this field trial is enabled, we will report VideoContentType RTP extension