diff --git a/libraries/AP_HAL_ChibiOS/hwdef/NucleoH743/hwdef-bl.dat b/libraries/AP_HAL_ChibiOS/hwdef/NucleoH743/hwdef-bl.dat
index 5eddd24b92..cf7c7a3eec 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/NucleoH743/hwdef-bl.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/NucleoH743/hwdef-bl.dat
@@ -7,9 +7,12 @@ MCU STM32H7xx STM32H743xx
 # crystal frequency
 OSCILLATOR_HZ 8000000
 
+define STM32_HSE_BYPASS
+
 # board ID for firmware load
 APJ_BOARD_ID 139
 
+# the nucleo seems to have trouble with flashing the last sector?
 FLASH_SIZE_KB 1920
 
 # bootloader is installed at zero offset
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/NucleoH743/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/NucleoH743/hwdef.dat
index dbc0f6eed6..a5038f6f24 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/NucleoH743/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/NucleoH743/hwdef.dat
@@ -7,9 +7,12 @@ MCU STM32H7xx STM32H743xx
 # crystal frequency
 OSCILLATOR_HZ 8000000
 
+define STM32_HSE_BYPASS
+
 # board ID for firmware load
 APJ_BOARD_ID 139
 
+# the nucleo seems to have trouble with flashing the last sector?
 FLASH_SIZE_KB 2048
 
 FLASH_RESERVE_START_KB 128