diff --git a/webrtc/modules/audio_coding/test/APITest.cc b/webrtc/modules/audio_coding/test/APITest.cc
index 1b9981341b..a4fc986153 100644
--- a/webrtc/modules/audio_coding/test/APITest.cc
+++ b/webrtc/modules/audio_coding/test/APITest.cc
@@ -678,7 +678,7 @@ void APITest::TestDelay(char side) {
   double averageEstimDelay = 0;
   double averageDelay = 0;
 
-  CircularBuffer estimDelayCB(100);
+  test::CircularBuffer estimDelayCB(100);
   estimDelayCB.SetArithMean(true);
 
   if (side == 'A') {
diff --git a/webrtc/modules/audio_coding/test/utility.cc b/webrtc/modules/audio_coding/test/utility.cc
index 5c1fc3f968..30bafd4a49 100644
--- a/webrtc/modules/audio_coding/test/utility.cc
+++ b/webrtc/modules/audio_coding/test/utility.cc
@@ -136,6 +136,8 @@ void PrintCodecs() {
 
 }
 
+namespace test {
+
 CircularBuffer::CircularBuffer(uint32_t len)
     : _buff(NULL),
       _idx(0),
@@ -265,6 +267,8 @@ int16_t CircularBuffer::Variance(double& var) {
   }
 }
 
+}  // namespace test
+
 bool FixedPayloadTypeCodec(const char* payloadName) {
   char fixPayloadTypeCodecs[NUM_CODECS_WITH_FIXED_PAYLOAD_TYPE][32] = { "PCMU",
       "PCMA", "GSM", "G723", "DVI4", "LPC", "PCMA", "G722", "QCELP", "CN",
diff --git a/webrtc/modules/audio_coding/test/utility.h b/webrtc/modules/audio_coding/test/utility.h
index 1a3e06d6c9..8af3675167 100644
--- a/webrtc/modules/audio_coding/test/utility.h
+++ b/webrtc/modules/audio_coding/test/utility.h
@@ -83,6 +83,9 @@ class ACMTestTimer {
   unsigned long _hour;
 };
 
+// To avoid clashes with CircularBuffer in APM.
+namespace test {
+
 class CircularBuffer {
  public:
   CircularBuffer(uint32_t len);
@@ -109,6 +112,8 @@ class CircularBuffer {
   double _sumSqr;
 };
 
+}  // namespace test
+
 int16_t ChooseCodec(CodecInst& codecInst);
 
 void PrintCodecs();