diff --git a/include/mmsystem.h b/include/mmsystem.h
index 27119e19ee3..e80271b2501 100644
--- a/include/mmsystem.h
+++ b/include/mmsystem.h
@@ -1302,6 +1302,7 @@ DECL_WINELIB_TYPE_AW(LPMIXERLINE)
 #define MIXERCONTROL_CONTROLTYPE_MONO		(MIXERCONTROL_CONTROLTYPE_BOOLEAN + 3)
 #define MIXERCONTROL_CONTROLTYPE_LOUDNESS	(MIXERCONTROL_CONTROLTYPE_BOOLEAN + 4)
 #define MIXERCONTROL_CONTROLTYPE_STEREOENH	(MIXERCONTROL_CONTROLTYPE_BOOLEAN + 5)
+#define MIXERCONTROL_CONTROLTYPE_BASS_BOOST     (MIXERCONTROL_CONTROLTYPE_BOOLEAN + 0x00002277)
 #define MIXERCONTROL_CONTROLTYPE_BUTTON		(MIXERCONTROL_CT_CLASS_SWITCH | MIXERCONTROL_CT_SC_SWITCH_BUTTON | MIXERCONTROL_CT_UNITS_BOOLEAN)
 #define MIXERCONTROL_CONTROLTYPE_DECIBELS	(MIXERCONTROL_CT_CLASS_NUMBER | MIXERCONTROL_CT_UNITS_DECIBELS)
 #define MIXERCONTROL_CONTROLTYPE_SIGNED		(MIXERCONTROL_CT_CLASS_NUMBER | MIXERCONTROL_CT_UNITS_SIGNED)