diff --git a/audio/audio_send_stream_unittest.cc b/audio/audio_send_stream_unittest.cc
index c5adca7a23..43e6c47865 100644
--- a/audio/audio_send_stream_unittest.cc
+++ b/audio/audio_send_stream_unittest.cc
@@ -84,7 +84,8 @@ std::unique_ptr<MockAudioEncoder> SetupAudioEncoderMock(
     const SdpAudioFormat& format) {
   for (const auto& spec : kCodecSpecs) {
     if (format == spec.format) {
-      std::unique_ptr<MockAudioEncoder> encoder(new MockAudioEncoder);
+      std::unique_ptr<MockAudioEncoder> encoder(
+          new testing::NiceMock<MockAudioEncoder>());
       ON_CALL(*encoder.get(), SampleRateHz())
           .WillByDefault(Return(spec.info.sample_rate_hz));
       ON_CALL(*encoder.get(), NumChannels())
@@ -185,6 +186,7 @@ struct ConfigHelper {
   }
 
   void SetupDefaultChannelProxy(bool audio_bwe_enabled) {
+    EXPECT_TRUE(channel_proxy_ == nullptr);
     channel_proxy_ = new testing::StrictMock<MockVoEChannelProxy>();
     EXPECT_CALL(*channel_proxy_, GetRtpRtcp(_, _))
         .WillRepeatedly(Invoke(
@@ -303,9 +305,9 @@ struct ConfigHelper {
   AudioProcessingStats audio_processing_stats_;
   SimulatedClock simulated_clock_;
   TimeInterval active_lifetime_;
-  MockRtcEventLog event_log_;
+  testing::NiceMock<MockRtcEventLog> event_log_;
   RtpTransportControllerSend rtp_transport_;
-  MockRtpRtcp rtp_rtcp_;
+  testing::NiceMock<MockRtpRtcp> rtp_rtcp_;
   MockRtcpRttStats rtcp_rtt_stats_;
   testing::NiceMock<MockLimitObserver> limit_observer_;
   BitrateAllocator bitrate_allocator_;
diff --git a/modules/audio_processing/include/mock_audio_processing.h b/modules/audio_processing/include/mock_audio_processing.h
index 8a1e463b23..e973d19264 100644
--- a/modules/audio_processing/include/mock_audio_processing.h
+++ b/modules/audio_processing/include/mock_audio_processing.h
@@ -136,7 +136,7 @@ class MockVoiceDetection : public VoiceDetection {
   MOCK_CONST_METHOD0(frame_size_ms, int());
 };
 
-class MockAudioProcessing : public AudioProcessing {
+class MockAudioProcessing : public testing::NiceMock<AudioProcessing> {
  public:
   MockAudioProcessing()
       : echo_cancellation_(new testing::NiceMock<MockEchoCancellation>()),
diff --git a/test/mock_audio_encoder_factory.h b/test/mock_audio_encoder_factory.h
index dea48da6c8..5b2ca33612 100644
--- a/test/mock_audio_encoder_factory.h
+++ b/test/mock_audio_encoder_factory.h
@@ -15,12 +15,13 @@
 #include <vector>
 
 #include "api/audio_codecs/audio_encoder_factory.h"
+#include "rtc_base/refcountedobject.h"
 #include "rtc_base/scoped_ref_ptr.h"
 #include "test/gmock.h"
 
 namespace webrtc {
 
-class MockAudioEncoderFactory : public AudioEncoderFactory {
+class MockAudioEncoderFactory : public testing::NiceMock<AudioEncoderFactory> {
  public:
   MOCK_METHOD0(GetSupportedEncoders, std::vector<AudioCodecSpec>());
   MOCK_METHOD1(QueryAudioEncoder,