diff --git a/api/ortc/ortcfactoryinterface.h b/api/ortc/ortcfactoryinterface.h
index 9937352831..ea25c8a3cb 100644
--- a/api/ortc/ortcfactoryinterface.h
+++ b/api/ortc/ortcfactoryinterface.h
@@ -15,6 +15,7 @@
 #include <string>
 #include <utility>  // For std::move.
 
+#include "api/mediaconstraintsinterface.h"
 #include "api/mediastreaminterface.h"
 #include "api/mediatypes.h"
 #include "api/ortc/ortcrtpreceiverinterface.h"
@@ -24,7 +25,6 @@
 #include "api/ortc/rtptransportinterface.h"
 #include "api/ortc/srtptransportinterface.h"
 #include "api/ortc/udptransportinterface.h"
-#include "api/peerconnectioninterface.h"
 #include "api/rtcerror.h"
 #include "api/rtpparameters.h"
 #include "rtc_base/network.h"
diff --git a/api/peerconnectioninterface.cc b/api/peerconnectioninterface.cc
index b4148d7480..05aa53f15b 100644
--- a/api/peerconnectioninterface.cc
+++ b/api/peerconnectioninterface.cc
@@ -192,6 +192,16 @@ PeerConnectionFactoryDependencies::PeerConnectionFactoryDependencies(
 PeerConnectionFactoryDependencies::~PeerConnectionFactoryDependencies() =
     default;
 
+rtc::scoped_refptr<PeerConnectionInterface>
+PeerConnectionFactoryInterface::CreatePeerConnection(
+    const PeerConnectionInterface::RTCConfiguration& configuration,
+    const MediaConstraintsInterface* constraints,
+    std::unique_ptr<cricket::PortAllocator> allocator,
+    std::unique_ptr<rtc::RTCCertificateGeneratorInterface> cert_generator,
+    PeerConnectionObserver* observer) {
+  return nullptr;
+}
+
 rtc::scoped_refptr<PeerConnectionInterface>
 PeerConnectionFactoryInterface::CreatePeerConnection(
     const PeerConnectionInterface::RTCConfiguration& configuration,
diff --git a/api/peerconnectioninterface.h b/api/peerconnectioninterface.h
index 1c32b69692..2b94ee8ad5 100644
--- a/api/peerconnectioninterface.h
+++ b/api/peerconnectioninterface.h
@@ -1233,6 +1233,15 @@ class PeerConnectionFactoryInterface : public rtc::RefCountInterface {
       std::unique_ptr<rtc::RTCCertificateGeneratorInterface> cert_generator,
       PeerConnectionObserver* observer);
 
+  // Deprecated; should use RTCConfiguration for everything that previously
+  // used constraints.
+  virtual rtc::scoped_refptr<PeerConnectionInterface> CreatePeerConnection(
+      const PeerConnectionInterface::RTCConfiguration& configuration,
+      const MediaConstraintsInterface* constraints,
+      std::unique_ptr<cricket::PortAllocator> allocator,
+      std::unique_ptr<rtc::RTCCertificateGeneratorInterface> cert_generator,
+      PeerConnectionObserver* observer);
+
   // Returns the capabilities of an RTP sender of type |kind|.
   // If for some reason you pass in MEDIA_TYPE_DATA, returns an empty structure.
   // TODO(orphis): Make pure virtual when all subclasses implement it.
diff --git a/api/test/mock_peerconnectioninterface.h b/api/test/mock_peerconnectioninterface.h
index 2e040decd8..58ca741033 100644
--- a/api/test/mock_peerconnectioninterface.h
+++ b/api/test/mock_peerconnectioninterface.h
@@ -88,12 +88,18 @@ class MockPeerConnectionInterface
                      const SessionDescriptionInterface*());
   MOCK_CONST_METHOD0(pending_remote_description,
                      const SessionDescriptionInterface*());
+  MOCK_METHOD2(CreateOffer,
+               void(CreateSessionDescriptionObserver*,
+                    const MediaConstraintsInterface*));
   MOCK_METHOD2(CreateOffer,
                void(CreateSessionDescriptionObserver*,
                     const RTCOfferAnswerOptions&));
   MOCK_METHOD2(CreateAnswer,
                void(CreateSessionDescriptionObserver*,
                     const RTCOfferAnswerOptions&));
+  MOCK_METHOD2(CreateAnswer,
+               void(CreateSessionDescriptionObserver*,
+                    const MediaConstraintsInterface*));
   MOCK_METHOD2(SetLocalDescription,
                void(SetSessionDescriptionObserver*,
                     SessionDescriptionInterface*));
diff --git a/pc/peerconnection.cc b/pc/peerconnection.cc
index 6c543f90ef..7bc25706f0 100644
--- a/pc/peerconnection.cc
+++ b/pc/peerconnection.cc
@@ -20,6 +20,7 @@
 #include "absl/memory/memory.h"
 #include "api/jsepicecandidate.h"
 #include "api/jsepsessiondescription.h"
+#include "api/mediaconstraintsinterface.h"
 #include "api/mediastreamproxy.h"
 #include "api/mediastreamtrackproxy.h"
 #include "call/call.h"
diff --git a/pc/peerconnection_integrationtest.cc b/pc/peerconnection_integrationtest.cc
index d9fa1d5abd..cc97e4ef7d 100644
--- a/pc/peerconnection_integrationtest.cc
+++ b/pc/peerconnection_integrationtest.cc
@@ -85,6 +85,7 @@ using webrtc::DtmfSender;
 using webrtc::DtmfSenderInterface;
 using webrtc::DtmfSenderObserverInterface;
 using webrtc::FakeVideoTrackRenderer;
+using webrtc::MediaConstraintsInterface;
 using webrtc::MediaStreamInterface;
 using webrtc::MediaStreamTrackInterface;
 using webrtc::MockCreateSessionDescriptionObserver;
diff --git a/pc/peerconnectionendtoend_unittest.cc b/pc/peerconnectionendtoend_unittest.cc
index 60da2d242c..427529c2c9 100644
--- a/pc/peerconnectionendtoend_unittest.cc
+++ b/pc/peerconnectionendtoend_unittest.cc
@@ -40,6 +40,7 @@ using testing::_;
 
 using webrtc::DataChannelInterface;
 using webrtc::FakeConstraints;
+using webrtc::MediaConstraintsInterface;
 using webrtc::MediaStreamInterface;
 using webrtc::PeerConnectionInterface;
 using webrtc::SdpSemantics;
diff --git a/pc/peerconnectioninterface_unittest.cc b/pc/peerconnectioninterface_unittest.cc
index 719fdbdd7f..2f6c0efbe0 100644
--- a/pc/peerconnectioninterface_unittest.cc
+++ b/pc/peerconnectioninterface_unittest.cc
@@ -417,6 +417,7 @@ using webrtc::AudioTrackInterface;
 using webrtc::DataBuffer;
 using webrtc::DataChannelInterface;
 using webrtc::IceCandidateInterface;
+using webrtc::MediaConstraintsInterface;
 using webrtc::MediaStream;
 using webrtc::MediaStreamInterface;
 using webrtc::MediaStreamTrackInterface;
diff --git a/pc/test/mock_peerconnection.h b/pc/test/mock_peerconnection.h
index 0a75b14772..d8cb5e381b 100644
--- a/pc/test/mock_peerconnection.h
+++ b/pc/test/mock_peerconnection.h
@@ -118,12 +118,18 @@ class MockPeerConnection
                      const SessionDescriptionInterface*());
   MOCK_CONST_METHOD0(pending_remote_description,
                      const SessionDescriptionInterface*());
+  MOCK_METHOD2(CreateOffer,
+               void(CreateSessionDescriptionObserver*,
+                    const MediaConstraintsInterface*));
   MOCK_METHOD2(CreateOffer,
                void(CreateSessionDescriptionObserver*,
                     const RTCOfferAnswerOptions&));
   MOCK_METHOD2(CreateAnswer,
                void(CreateSessionDescriptionObserver*,
                     const RTCOfferAnswerOptions&));
+  MOCK_METHOD2(CreateAnswer,
+               void(CreateSessionDescriptionObserver*,
+                    const MediaConstraintsInterface*));
   MOCK_METHOD2(SetLocalDescription,
                void(SetSessionDescriptionObserver*,
                     SessionDescriptionInterface*));
diff --git a/pc/test/peerconnectiontestwrapper.cc b/pc/test/peerconnectiontestwrapper.cc
index 03dabb554e..fc699d3143 100644
--- a/pc/test/peerconnectiontestwrapper.cc
+++ b/pc/test/peerconnectiontestwrapper.cc
@@ -26,6 +26,7 @@
 using webrtc::FakeConstraints;
 using webrtc::FakeVideoTrackRenderer;
 using webrtc::IceCandidateInterface;
+using webrtc::MediaConstraintsInterface;
 using webrtc::MediaStreamInterface;
 using webrtc::MediaStreamTrackInterface;
 using webrtc::MockSetSessionDescriptionObserver;
diff --git a/pc/webrtcsessiondescriptionfactory.cc b/pc/webrtcsessiondescriptionfactory.cc
index 808e411a39..22551437e3 100644
--- a/pc/webrtcsessiondescriptionfactory.cc
+++ b/pc/webrtcsessiondescriptionfactory.cc
@@ -18,6 +18,7 @@
 #include "absl/memory/memory.h"
 #include "api/jsep.h"
 #include "api/jsepsessiondescription.h"
+#include "api/mediaconstraintsinterface.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/sslidentity.h"