diff --git a/libraries/AP_HAL_ChibiOS/hwdef/F4BY_F427/hwdef-bl.dat b/libraries/AP_HAL_ChibiOS/hwdef/F4BY_F427/hwdef-bl.dat
index b95c0fb7ebb7a..60889f42de5ab 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/F4BY_F427/hwdef-bl.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/F4BY_F427/hwdef-bl.dat
@@ -3,7 +3,7 @@
 
 MCU STM32F4xx STM32F427xx
 
-APJ_BOARD_ID 7221
+APJ_BOARD_ID AP_HW_F4BY_F427
 
 OSCILLATOR_HZ 8000000