diff --git a/libraries/AP_HAL_ChibiOS/hwdef/MatekL431-GPS/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/MatekL431-GPS/hwdef.dat
index 5c858285a7..585fc4901d 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/MatekL431-GPS/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/MatekL431-GPS/hwdef.dat
@@ -13,6 +13,7 @@ define HAL_PERIPH_GPS_PORT_DEFAULT 2
 define GPS_MOVING_BASELINE 1
 
 define HAL_PERIPH_ENABLE_MAG
+define HAL_PROBE_EXTERNAL_I2C_COMPASSES
 
 define HAL_COMPASS_MAX_SENSORS 1