diff --git a/talk/app/webrtc/dtmfsender_unittest.cc b/talk/app/webrtc/dtmfsender_unittest.cc
index f686aa2ccc..ba2e163f13 100644
--- a/talk/app/webrtc/dtmfsender_unittest.cc
+++ b/talk/app/webrtc/dtmfsender_unittest.cc
@@ -34,6 +34,7 @@
 #include "talk/app/webrtc/audiotrack.h"
 #include "webrtc/base/gunit.h"
 #include "webrtc/base/logging.h"
+#include "webrtc/base/refcount.h"
 #include "webrtc/base/timeutils.h"
 
 using webrtc::AudioTrackInterface;
@@ -45,7 +46,7 @@ using webrtc::DtmfSenderObserverInterface;
 static const char kTestAudioLabel[] = "test_audio_track";
 static const int kMaxWaitMs = 3000;
 
-class FakeDtmfObserver : public DtmfSenderObserverInterface {
+class FakeDtmfObserver : public DtmfSenderObserverInterface, RefCountInterface {
  public:
   FakeDtmfObserver() : completed_(false) {}
 
diff --git a/talk/media/webrtc/fakewebrtcvideocapturemodule.h b/talk/media/webrtc/fakewebrtcvideocapturemodule.h
index 3c515555e7..7540fcf1d4 100644
--- a/talk/media/webrtc/fakewebrtcvideocapturemodule.h
+++ b/talk/media/webrtc/fakewebrtcvideocapturemodule.h
@@ -101,8 +101,8 @@ class FakeWebRtcVideoCaptureModule : public webrtc::VideoCaptureModule {
       const webrtc::VideoCodec& codec) override {
     return NULL;  // not implemented
   }
-  int32_t AddRef() override { return 0; }
-  int32_t Release() override {
+  int32_t AddRef() const override { return 0; }
+  int32_t Release() const override {
     delete this;
     return 0;
   }
diff --git a/webrtc/base/bind_unittest.cc b/webrtc/base/bind_unittest.cc
index d38729d9df..fa47d279f5 100644
--- a/webrtc/base/bind_unittest.cc
+++ b/webrtc/base/bind_unittest.cc
@@ -108,6 +108,7 @@ EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(F);
 EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(RefCountedObject<RefCountInterface>);
 EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(RefCountedObject<B>);
 EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(RefCountedObject<C>);
+EXPECT_IS_CAPTURED_AS_SCOPED_REFPTR(const RefCountedObject<RefCountInterface>);
 
 TEST(BindTest, BindToMethod) {
   MethodBindTester object = {0};
diff --git a/webrtc/base/refcount.h b/webrtc/base/refcount.h
index 49f3777bea..dbad2eba76 100644
--- a/webrtc/base/refcount.h
+++ b/webrtc/base/refcount.h
@@ -20,8 +20,8 @@ namespace rtc {
 // Reference count interface.
 class RefCountInterface {
  public:
-  virtual int AddRef() = 0;
-  virtual int Release() = 0;
+  virtual int AddRef() const = 0;
+  virtual int Release() const = 0;
  protected:
   virtual ~RefCountInterface() {}
 };
@@ -95,11 +95,11 @@ class RefCountedObject : public T {
   : T(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11), ref_count_(0) {
   }
 
-  virtual int AddRef() {
+  int AddRef() const override {
     return AtomicOps::Increment(&ref_count_);
   }
 
-  virtual int Release() {
+  int Release() const override {
     int count = AtomicOps::Decrement(&ref_count_);
     if (!count) {
       delete this;
@@ -121,7 +121,7 @@ class RefCountedObject : public T {
   virtual ~RefCountedObject() {
   }
 
-  volatile int ref_count_;
+  mutable volatile int ref_count_;
 };
 
 }  // namespace rtc
diff --git a/webrtc/modules/audio_device/include/fake_audio_device.h b/webrtc/modules/audio_device/include/fake_audio_device.h
index 4c0739a003..8b154794c7 100644
--- a/webrtc/modules/audio_device/include/fake_audio_device.h
+++ b/webrtc/modules/audio_device/include/fake_audio_device.h
@@ -16,8 +16,8 @@ class FakeAudioDeviceModule : public AudioDeviceModule {
  public:
   FakeAudioDeviceModule() {}
   virtual ~FakeAudioDeviceModule() {}
-  virtual int32_t AddRef() { return 0; }
-  virtual int32_t Release() { return 0; }
+  virtual int32_t AddRef() const { return 0; }
+  virtual int32_t Release() const { return 0; }
   virtual int32_t RegisterEventObserver(AudioDeviceObserver* eventCallback) {
     return 0;
   }
diff --git a/webrtc/modules/interface/module.h b/webrtc/modules/interface/module.h
index 529138de42..ffd3065a5c 100644
--- a/webrtc/modules/interface/module.h
+++ b/webrtc/modules/interface/module.h
@@ -64,13 +64,13 @@ class RefCountedModule : public Module {
  public:
   // Increase the reference count by one.
   // Returns the incremented reference count.
-  virtual int32_t AddRef() = 0;
+  virtual int32_t AddRef() const = 0;
 
   // Decrease the reference count by one.
   // Returns the decreased reference count.
   // Returns 0 if the last reference was just released.
   // When the reference count reaches 0 the object will self-destruct.
-  virtual int32_t Release() = 0;
+  virtual int32_t Release() const = 0;
 
  protected:
   ~RefCountedModule() override = default;
diff --git a/webrtc/modules/video_capture/include/mock/mock_video_capture.h b/webrtc/modules/video_capture/include/mock/mock_video_capture.h
index 0a15c445ed..c030c02aee 100644
--- a/webrtc/modules/video_capture/include/mock/mock_video_capture.h
+++ b/webrtc/modules/video_capture/include/mock/mock_video_capture.h
@@ -22,8 +22,8 @@ class MockVideoCaptureModule : public VideoCaptureModule {
   MOCK_METHOD0(Process, int32_t());
 
   // from RefCountedModule
-  MOCK_METHOD0(AddRef, int32_t());
-  MOCK_METHOD0(Release, int32_t());
+  MOCK_CONST_METHOD0(AddRef, int32_t());
+  MOCK_CONST_METHOD0(Release, int32_t());
 
   // from VideoCaptureModule
   MOCK_METHOD1(RegisterCaptureDataCallback,
diff --git a/webrtc/system_wrappers/interface/ref_count.h b/webrtc/system_wrappers/interface/ref_count.h
index 68616662e9..bbf2c605e8 100644
--- a/webrtc/system_wrappers/interface/ref_count.h
+++ b/webrtc/system_wrappers/interface/ref_count.h
@@ -61,11 +61,11 @@ class RefCountImpl : public T {
   RefCountImpl(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5)
       : T(p1, p2, p3, p4, p5), ref_count_(0) {}
 
-  virtual int32_t AddRef() {
+  int32_t AddRef() const override {
     return ++ref_count_;
   }
 
-  virtual int32_t Release() {
+  int32_t Release() const override {
     int32_t ref_count;
     ref_count = --ref_count_;
     if (ref_count == 0)
@@ -74,7 +74,7 @@ class RefCountImpl : public T {
   }
 
  protected:
-  Atomic32 ref_count_;
+  mutable Atomic32 ref_count_;
 };
 
 }  // namespace webrtc