diff --git a/libraries/AP_HAL_ChibiOS/hwdef/f103-RangeFinder/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/f103-RangeFinder/hwdef.dat
index 1e2f9f3076..36fad306c4 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/f103-RangeFinder/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/f103-RangeFinder/hwdef.dat
@@ -10,7 +10,7 @@ define AIRSPEED_MAX_SENSORS 1
 
 define HAL_PERIPH_ENABLE_RANGEFINDER
 
-define HAL_SERIAL3_PROTOCOL SerialProtocol_Rangefinder
+define AP_PERIPH_RANGEFINDER_PORT_DEFAULT 3
 
 # we're too low on flash with old compiler for bootloader
 define HAL_NO_ROMFS_SUPPORT