diff --git a/src/modules/audio_coding/main/source/acm_celt.cc b/src/modules/audio_coding/main/source/acm_celt.cc
index 1b5477ba27..5b12f32492 100644
--- a/src/modules/audio_coding/main/source/acm_celt.cc
+++ b/src/modules/audio_coding/main/source/acm_celt.cc
@@ -49,7 +49,7 @@ int16_t ACMCELT::DecodeSafe(uint8_t* /* bitStream */,
                             int16_t /* bitStreamLenByte */,
                             int16_t* /* audio */,
                             int16_t* /* audioSamples */,
-                            int8_t* /* speechType */) {
+                            WebRtc_Word8* /* speechType */) {
   return -1;
 }
 
@@ -157,7 +157,7 @@ int16_t ACMCELT::DecodeSafe(uint8_t* /* bitStream */,
                             int16_t /* bitStreamLenByte */,
                             int16_t* /* audio */,
                             int16_t* /* audioSamples */,
-                            int8_t* /* speechType */) {
+                            WebRtc_Word8* /* speechType */) {
   return 0;
 }
 
diff --git a/src/modules/audio_coding/main/source/acm_celt.h b/src/modules/audio_coding/main/source/acm_celt.h
index 8205244969..776bd7fc55 100644
--- a/src/modules/audio_coding/main/source/acm_celt.h
+++ b/src/modules/audio_coding/main/source/acm_celt.h
@@ -39,7 +39,9 @@ class ACMCELT : public ACMGenericCodec {
       int16_t /* bitStreamLenByte */,
       int16_t* /* audio */,
       int16_t* /* audioSamples */,
-      int8_t* /* speechType */);
+      // TODO(leozwang): use int8_t here when WebRtc_Word8 is properly typed.
+      // http://code.google.com/p/webrtc/issues/detail?id=311
+      WebRtc_Word8* /* speechType */);
 
   int32_t CodecDef(WebRtcNetEQ_CodecDef& codecDef, const CodecInst& codecInst);