diff --git a/webrtc/audio/audio_send_stream.cc b/webrtc/audio/audio_send_stream.cc
index cb4c1b041c..d8bc84858a 100644
--- a/webrtc/audio/audio_send_stream.cc
+++ b/webrtc/audio/audio_send_stream.cc
@@ -82,6 +82,7 @@ AudioSendStream::AudioSendStream(
       channel_proxy_->SetSendAudioLevelIndicationStatus(true, extension.id);
     } else if (extension.uri == RtpExtension::kTransportSequenceNumberUri) {
       channel_proxy_->EnableSendTransportSequenceNumber(extension.id);
+      congestion_controller->EnablePeriodicAlrProbing(true);
     } else {
       RTC_NOTREACHED() << "Registering unsupported RTP extension.";
     }