diff --git a/media/libmedia/AudioSystem.cpp b/media/libmedia/AudioSystem.cpp
index 28892df..bbe4d8d 100644
--- a/media/libmedia/AudioSystem.cpp
+++ b/media/libmedia/AudioSystem.cpp
@@ -538,6 +538,7 @@
 
 status_t AudioSystem::setPhoneState(audio_mode_t state)
 {
+    if (uint32_t(state) >= AUDIO_MODE_CNT) return BAD_VALUE;
     const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
     if (aps == 0) return PERMISSION_DENIED;