diff --git a/pc/peer_connection.cc b/pc/peer_connection.cc
index ec2f656422..878bcb5f6f 100644
--- a/pc/peer_connection.cc
+++ b/pc/peer_connection.cc
@@ -7063,6 +7063,7 @@ bool PeerConnection::OnTransportChanged(
     RtpTransportInternal* rtp_transport,
     rtc::scoped_refptr<DtlsTransport> dtls_transport,
     MediaTransportInterface* media_transport) {
+  RTC_DCHECK_RUN_ON(network_thread());
   RTC_DCHECK_RUNS_SERIALIZED(&use_media_transport_race_checker_);
   bool ret = true;
   auto base_channel = GetChannel(mid);
@@ -7076,7 +7077,7 @@ bool PeerConnection::OnTransportChanged(
   if (use_media_transport_) {
     // Only pass media transport to call object if media transport is used
     // for media (and not data channel).
-    call_->MediaTransportChange(media_transport);
+    call_ptr_->MediaTransportChange(media_transport);
   }
 
   return ret;
diff --git a/pc/peer_connection.h b/pc/peer_connection.h
index 9c2222ac60..9e9abe40b0 100644
--- a/pc/peer_connection.h
+++ b/pc/peer_connection.h
@@ -1030,8 +1030,7 @@ class PeerConnection : public PeerConnectionInternal,
   bool OnTransportChanged(const std::string& mid,
                           RtpTransportInternal* rtp_transport,
                           rtc::scoped_refptr<DtlsTransport> dtls_transport,
-                          MediaTransportInterface* media_transport) override
-      RTC_RUN_ON(worker_thread());
+                          MediaTransportInterface* media_transport) override;
 
   // Returns the observer. Will crash on CHECK if the observer is removed.
   PeerConnectionObserver* Observer() const RTC_RUN_ON(signaling_thread());
@@ -1151,11 +1150,13 @@ class PeerConnection : public PeerConnectionInternal,
 
   bool remote_peer_supports_msid_ RTC_GUARDED_BY(signaling_thread()) = false;
 
+  // The unique_ptr belongs to the worker thread, but the Call object manages
+  // its own thread safety.
   std::unique_ptr<Call> call_ RTC_GUARDED_BY(worker_thread());
 
   // Points to the same thing as `call_`. Since it's const, we may read the
-  // pointer (but not touch the object) from any thread.
-  Call* const call_ptr_ RTC_PT_GUARDED_BY(worker_thread());
+  // pointer from any thread.
+  Call* const call_ptr_;
 
   std::unique_ptr<StatsCollector> stats_
       RTC_GUARDED_BY(signaling_thread());  // A pointer is passed to senders_