diff --git a/libao2/audio_out.h b/libao2/audio_out.h
index b730d7cf8f..264e575636 100644
--- a/libao2/audio_out.h
+++ b/libao2/audio_out.h
@@ -71,6 +71,7 @@ extern int ao_buffersize;
 #define CONTROL_NA -3
 
 #define AOCONTROL_SET_DEVICE 1
-#define AOCONTROL_QUERY_FORMAT 2
-
-
+#define AOCONTROL_GET_DEVICE 2
+#define AOCONTROL_QUERY_FORMAT 3
+#define AOCONTROL_GET_VOLUME 4
+#define AOCONTROL_SET_VOLUME 5