diff --git a/include/audiomanager/AudioManager.h b/include/audiomanager/AudioManager.h
index 917d9a7..203623d 100644
--- a/include/audiomanager/AudioManager.h
+++ b/include/audiomanager/AudioManager.h
@@ -22,6 +22,7 @@
 // must be kept in sync with definitions in AudioPlaybackConfiguration.java
 #define PLAYER_PIID_INVALID -1
 
+// TODO (b/309532236) remove manual IAudioManager impl in favor of AIDL.
 typedef enum {
     PLAYER_TYPE_SLES_AUDIOPLAYER_BUFFERQUEUE = 11,
     PLAYER_TYPE_SLES_AUDIOPLAYER_URI_FD = 12,
@@ -60,6 +61,7 @@
     PLAYER_MUTE_CLIENT_VOLUME = (1 << 4),
     PLAYER_MUTE_VOLUME_SHAPER = (1 << 5),
     PLAYER_MUTE_PORT_VOLUME = (1 << 6),
+    PLAYER_MUTE_OP_AUDIO_CONTROL = (1 << 7),
 };
 
 struct mute_state_t {
@@ -77,6 +79,8 @@
     bool muteFromVolumeShaper = false;
     /** Flag used when volume is muted by port volume. */
     bool muteFromPortVolume = false;
+    /** Flag used when volume is muted by audio control op. */
+    bool muteFromOpAudioControl = false;
 
     explicit operator int() const
     {
@@ -87,6 +91,7 @@
         result |= muteFromClientVolume * PLAYER_MUTE_CLIENT_VOLUME;
         result |= muteFromVolumeShaper * PLAYER_MUTE_VOLUME_SHAPER;
         result |= muteFromPortVolume * PLAYER_MUTE_PORT_VOLUME;
+        result |= muteFromOpAudioControl * PLAYER_MUTE_OP_AUDIO_CONTROL;
         return result;
     }