diff --git a/pc/jsep_transport_controller.cc b/pc/jsep_transport_controller.cc
index 8e15a3dbac..c9ed4d573f 100644
--- a/pc/jsep_transport_controller.cc
+++ b/pc/jsep_transport_controller.cc
@@ -1450,7 +1450,6 @@ void JsepTransportController::OnTransportStateChanged_n(
 }
 
 void JsepTransportController::OnMediaTransportStateChanged_n() {
-  SignalMediaTransportStateChanged();
   UpdateAggregateStates_n();
 }
 
diff --git a/pc/jsep_transport_controller.h b/pc/jsep_transport_controller.h
index d575592f1e..c95a62d9fd 100644
--- a/pc/jsep_transport_controller.h
+++ b/pc/jsep_transport_controller.h
@@ -287,10 +287,6 @@ class JsepTransportController : public sigslot::has_slots<> {
 
   sigslot::signal1<rtc::SSLHandshakeError> SignalDtlsHandshakeError;
 
-  // TODO(mellem): Delete this signal once PeerConnection no longer
-  // uses it to determine data channel state.
-  sigslot::signal<> SignalMediaTransportStateChanged;
-
  private:
   RTCError ApplyDescription_n(bool local,
                               SdpType type,
diff --git a/pc/peer_connection.cc b/pc/peer_connection.cc
index 65f1283e49..a80cf5a991 100644
--- a/pc/peer_connection.cc
+++ b/pc/peer_connection.cc
@@ -6825,13 +6825,6 @@ bool PeerConnection::SetupDataChannelTransport_n(const std::string& mid) {
   data_channel_transport_invoker_ = std::make_unique<rtc::AsyncInvoker>();
   data_channel_transport_->SetDataSink(this);
   sctp_mid_ = mid;
-  // TODO(mellem):  Handling data channel state through media transport is
-  // deprecated.  Delete these lines when downstream implementations call
-  // DataChannelSink::OnStateChanged().
-  transport_controller_->SignalMediaTransportStateChanged.connect(
-      this, &PeerConnection::OnMediaTransportStateChanged_n);
-  // Check the initial state right away, in case transport is already writable.
-  OnMediaTransportStateChanged_n();
   return true;
 }
 
@@ -6842,9 +6835,6 @@ void PeerConnection::TeardownDataChannelTransport_n() {
   RTC_LOG(LS_INFO) << "Tearing down data channel transport for mid="
                    << *sctp_mid_;
 
-  // TODO(mellem):  Delete this line when downstream implementations call
-  // DataChannelSink::OnStateChanged().
-  transport_controller_->SignalMediaTransportStateChanged.disconnect(this);
   // |sctp_mid_| may still be active through an SCTP transport.  If not, unset
   // it.
   if (!sctp_transport_) {
@@ -6855,25 +6845,6 @@ void PeerConnection::TeardownDataChannelTransport_n() {
   data_channel_transport_ = nullptr;
 }
 
-// TODO(mellem):  Handling of data channel state through the media transport
-// callback is deprecated.  This function should be deleted once downstream
-// implementations call DataChannelSink::OnStateChanged().
-void PeerConnection::OnMediaTransportStateChanged_n() {
-  if (!sctp_mid_ || transport_controller_->GetMediaTransportState(*sctp_mid_) !=
-                        MediaTransportState::kWritable) {
-    return;
-  }
-  data_channel_transport_invoker_->AsyncInvoke<void>(
-      RTC_FROM_HERE, signaling_thread(), [this] {
-        RTC_DCHECK_RUN_ON(signaling_thread());
-        data_channel_transport_ready_to_send_ = true;
-        if (data_channel_transport_negotiated_) {
-          SignalDataChannelTransportWritable_s(
-              data_channel_transport_ready_to_send_);
-        }
-      });
-}
-
 // Returns false if bundle is enabled and rtcp_mux is disabled.
 bool PeerConnection::ValidateBundleSettings(const SessionDescription* desc) {
   bool bundle_enabled = desc->HasGroup(cricket::GROUP_TYPE_BUNDLE);
diff --git a/pc/peer_connection.h b/pc/peer_connection.h
index 5d57529642..da72687a70 100644
--- a/pc/peer_connection.h
+++ b/pc/peer_connection.h
@@ -1049,7 +1049,6 @@ class PeerConnection : public PeerConnectionInternal,
 
   bool SetupDataChannelTransport_n(const std::string& mid)
       RTC_RUN_ON(network_thread());
-  void OnMediaTransportStateChanged_n() RTC_RUN_ON(network_thread());
   void TeardownDataChannelTransport_n() RTC_RUN_ON(network_thread());
 
   bool ValidateBundleSettings(const cricket::SessionDescription* desc);