diff --git a/services/audioflinger/AudioPolicyService.cpp b/services/audioflinger/AudioPolicyService.cpp
index 0d13970..c32fc6b 100644
--- a/services/audioflinger/AudioPolicyService.cpp
+++ b/services/audioflinger/AudioPolicyService.cpp
@@ -373,6 +373,7 @@
     if (uint32_t(stream) >= AUDIO_STREAM_CNT) {
         return BAD_VALUE;
     }
+    Mutex::Autolock _l(mLock);
     mpAudioPolicy->init_stream_volume(mpAudioPolicy, stream, indexMin, indexMax);
     return NO_ERROR;
 }
@@ -390,7 +391,7 @@
     if (uint32_t(stream) >= AUDIO_STREAM_CNT) {
         return BAD_VALUE;
     }
-
+    Mutex::Autolock _l(mLock);
     if (mpAudioPolicy->set_stream_volume_index_for_device) {
         return mpAudioPolicy->set_stream_volume_index_for_device(mpAudioPolicy,
                                                                 stream,
@@ -411,6 +412,7 @@
     if (uint32_t(stream) >= AUDIO_STREAM_CNT) {
         return BAD_VALUE;
     }
+    Mutex::Autolock _l(mLock);
     if (mpAudioPolicy->get_stream_volume_index_for_device) {
         return mpAudioPolicy->get_stream_volume_index_for_device(mpAudioPolicy,
                                                                 stream,