diff --git a/webrtc/modules/audio_coding/main/acm2/codec_owner_unittest.cc b/webrtc/modules/audio_coding/main/acm2/codec_owner_unittest.cc
index ec1bb0df2b..9c17073339 100644
--- a/webrtc/modules/audio_coding/main/acm2/codec_owner_unittest.cc
+++ b/webrtc/modules/audio_coding/main/acm2/codec_owner_unittest.cc
@@ -56,6 +56,41 @@ class CodecOwnerTest : public ::testing::Test {
                 encoded_info.send_even_if_empty);
   }
 
+  // Verify that the speech encoder's Reset method is called when CNG or RED
+  // (or both) are switched on, but not when they're switched off.
+  void TestCngAndRedResetSpeechEncoder(bool use_cng, bool use_red) {
+    MockAudioEncoder speech_encoder;
+    EXPECT_CALL(speech_encoder, NumChannels())
+        .WillRepeatedly(Return(1));
+    EXPECT_CALL(speech_encoder, Max10MsFramesInAPacket())
+        .WillRepeatedly(Return(2));
+    EXPECT_CALL(speech_encoder, SampleRateHz())
+        .WillRepeatedly(Return(8000));
+    {
+      InSequence s;
+      EXPECT_CALL(speech_encoder, Mark("start off"));
+      EXPECT_CALL(speech_encoder, Mark("switch on"));
+      if (use_cng || use_red)
+        EXPECT_CALL(speech_encoder, Reset());
+      EXPECT_CALL(speech_encoder, Mark("start on"));
+      if (use_cng || use_red)
+        EXPECT_CALL(speech_encoder, Reset());
+      EXPECT_CALL(speech_encoder, Mark("switch off"));
+      EXPECT_CALL(speech_encoder, Die());
+    }
+
+    int cng_pt = use_cng ? 17 : -1;
+    int red_pt = use_red ? 19 : -1;
+    speech_encoder.Mark("start off");
+    codec_owner_.SetEncoders(&speech_encoder, -1, VADNormal, -1);
+    speech_encoder.Mark("switch on");
+    codec_owner_.ChangeCngAndRed(cng_pt, VADNormal, red_pt);
+    speech_encoder.Mark("start on");
+    codec_owner_.SetEncoders(&speech_encoder, cng_pt, VADNormal, red_pt);
+    speech_encoder.Mark("switch off");
+    codec_owner_.ChangeCngAndRed(-1, VADNormal, -1);
+  }
+
   CodecOwner codec_owner_;
   uint32_t timestamp_;
 };
@@ -145,5 +180,21 @@ TEST_F(CodecOwnerTest, ExternalEncoder) {
   EXPECT_EQ(2u, info.encoded_timestamp);
 }
 
+TEST_F(CodecOwnerTest, CngResetsSpeechEncoder) {
+  TestCngAndRedResetSpeechEncoder(true, false);
+}
+
+TEST_F(CodecOwnerTest, RedResetsSpeechEncoder) {
+  TestCngAndRedResetSpeechEncoder(false, true);
+}
+
+TEST_F(CodecOwnerTest, CngAndRedResetsSpeechEncoder) {
+  TestCngAndRedResetSpeechEncoder(true, true);
+}
+
+TEST_F(CodecOwnerTest, NoCngAndRedNoSpeechEncoderReset) {
+  TestCngAndRedResetSpeechEncoder(false, false);
+}
+
 }  // namespace acm2
 }  // namespace webrtc