diff --git a/call/rtp_transport_controller_send.cc b/call/rtp_transport_controller_send.cc
index c9388e47aa..fc4f483087 100644
--- a/call/rtp_transport_controller_send.cc
+++ b/call/rtp_transport_controller_send.cc
@@ -559,11 +559,10 @@ void RtpTransportControllerSend::OnReceivedRtcpReceiverReport(
 
 void RtpTransportControllerSend::OnAddPacket(
     const RtpPacketSendInfo& packet_info) {
-  feedback_demuxer_.AddPacket(packet_info);
-
   Timestamp creation_time = Timestamp::Millis(clock_->TimeInMilliseconds());
   task_queue_.PostTask([this, packet_info, creation_time]() {
     RTC_DCHECK_RUN_ON(&task_queue_);
+    feedback_demuxer_.AddPacket(packet_info);
     transport_feedback_adapter_.AddPacket(
         packet_info,
         send_side_bwe_with_overhead_ ? transport_overhead_bytes_per_packet_ : 0,
diff --git a/modules/congestion_controller/rtp/transport_feedback_demuxer.cc b/modules/congestion_controller/rtp/transport_feedback_demuxer.cc
index 62b85b10b8..29accb5be0 100644
--- a/modules/congestion_controller/rtp/transport_feedback_demuxer.cc
+++ b/modules/congestion_controller/rtp/transport_feedback_demuxer.cc
@@ -44,6 +44,10 @@ void TransportFeedbackDemuxer::DeRegisterStreamFeedbackObserver(
 }
 
 void TransportFeedbackDemuxer::AddPacket(const RtpPacketSendInfo& packet_info) {
+  // Currently called on the send transport queue.
+  // TODO(tommi): When registration/unregistration as well as
+  // OnTransportFeedback callbacks occur on the transport queue, we can remove
+  // this lock.
   MutexLock lock(&lock_);
 
   StreamFeedbackObserver::StreamPacketInfo info;