diff --git a/pc/data_channel_controller.cc b/pc/data_channel_controller.cc
index 39a31e625d..92cdba3119 100644
--- a/pc/data_channel_controller.cc
+++ b/pc/data_channel_controller.cc
@@ -165,6 +165,11 @@ void DataChannelController::SetupDataChannelTransport_n() {
   NotifyDataChannelsOfTransportCreated();
 }
 
+void DataChannelController::PrepareForShutdown() {
+  RTC_DCHECK_RUN_ON(signaling_thread());
+  signaling_safety_.reset();
+}
+
 void DataChannelController::TeardownDataChannelTransport_n() {
   RTC_DCHECK_RUN_ON(network_thread());
   if (data_channel_transport()) {
diff --git a/pc/data_channel_controller.h b/pc/data_channel_controller.h
index 0a46069274..f71e7a45a4 100644
--- a/pc/data_channel_controller.h
+++ b/pc/data_channel_controller.h
@@ -64,6 +64,9 @@ class DataChannelController : public SctpDataChannelControllerInterface,
   void OnReadyToSend() override;
   void OnTransportClosed(RTCError error) override;
 
+  // Called as part of destroying the owning PeerConnection.
+  void PrepareForShutdown();
+
   // Called from PeerConnection::SetupDataChannelTransport_n
   void SetupDataChannelTransport_n();
   // Called from PeerConnection::TeardownDataChannelTransport_n
diff --git a/pc/peer_connection.cc b/pc/peer_connection.cc
index dc3e901806..f365601287 100644
--- a/pc/peer_connection.cc
+++ b/pc/peer_connection.cc
@@ -1924,13 +1924,15 @@ void PeerConnection::Close() {
     event_log_.reset();
   });
   ReportUsagePattern();
-  // The .h file says that observer can be discarded after close() returns.
-  // Make sure this is true.
-  observer_ = nullptr;
 
   // Signal shutdown to the sdp handler. This invalidates weak pointers for
   // internal pending callbacks.
   sdp_handler_->PrepareForShutdown();
+  data_channel_controller_.PrepareForShutdown();
+
+  // The .h file says that observer can be discarded after close() returns.
+  // Make sure this is true.
+  observer_ = nullptr;
 }
 
 void PeerConnection::SetIceConnectionState(IceConnectionState new_state) {