diff --git a/src/drivers/drv_tone_alarm.h b/src/drivers/drv_tone_alarm.h
index b7981e9c4b..19f792d19c 100644
--- a/src/drivers/drv_tone_alarm.h
+++ b/src/drivers/drv_tone_alarm.h
@@ -149,6 +149,7 @@ enum {
 	TONE_GPS_WARNING_TUNE,
 	TONE_ARMING_FAILURE_TUNE,
 	TONE_PARACHUTE_RELEASE_TUNE,
+	TONE_EKF_WARNING_TUNE,
 	TONE_NUMBER_OF_TUNES
 };
 
diff --git a/src/drivers/stm32/tone_alarm/tone_alarm.cpp b/src/drivers/stm32/tone_alarm/tone_alarm.cpp
index 810f4aacc4..03c7bd399f 100644
--- a/src/drivers/stm32/tone_alarm/tone_alarm.cpp
+++ b/src/drivers/stm32/tone_alarm/tone_alarm.cpp
@@ -336,6 +336,7 @@ ToneAlarm::ToneAlarm() :
 	_default_tunes[TONE_GPS_WARNING_TUNE] = "MFT255L4AAAL1F#";					//gps warning slow
 	_default_tunes[TONE_ARMING_FAILURE_TUNE] = "MFT255L4<<<BAP";
 	_default_tunes[TONE_PARACHUTE_RELEASE_TUNE] = "MFT255L16agagagag";			// parachute release
+	_default_tunes[TONE_EKF_WARNING_TUNE] = "MFT255L8ddd#d#eeff";				// ekf warning
 
 	_tune_names[TONE_STARTUP_TUNE] = "startup";			// startup tune
 	_tune_names[TONE_ERROR_TUNE] = "error";				// ERROR tone
@@ -348,6 +349,7 @@ ToneAlarm::ToneAlarm() :
 	_tune_names[TONE_GPS_WARNING_TUNE] = "gps_warning";	            // gps warning
 	_tune_names[TONE_ARMING_FAILURE_TUNE] = "arming_failure";            //fail to arm
 	_tune_names[TONE_PARACHUTE_RELEASE_TUNE] = "parachute_release";	// parachute release
+	_tune_names[TONE_EKF_WARNING_TUNE] = "ekf_warning";				// ekf warning
 }
 
 ToneAlarm::~ToneAlarm()