diff --git a/libraries/AP_HAL_ChibiOS/hwdef/Here4AP/hwdef-bl.dat b/libraries/AP_HAL_ChibiOS/hwdef/Here4AP/hwdef-bl.dat
index 2468fe4167..6122a9af7e 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/Here4AP/hwdef-bl.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/Here4AP/hwdef-bl.dat
@@ -50,7 +50,6 @@ PA14 JTCK-SWCLK SWD
 
 # order of UARTs
 SERIAL_ORDER
-define HAL_USE_UART FALSE
 
 # setup for blanking LEDs in bootloader
 define AP_BOOTLOADER_CUSTOM_HERE4
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/Hitec-Airspeed/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/Hitec-Airspeed/hwdef.dat
index b9e7df2f27..efef7c8dc2 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/Hitec-Airspeed/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/Hitec-Airspeed/hwdef.dat
@@ -28,7 +28,6 @@ FLASH_SIZE_KB 128
 # order of UARTs
 # SERIAL_ORDER USART1
 SERIAL_ORDER
-define HAL_USE_UART FALSE
 define AP_HAL_UARTDRIVER_ENABLED 0
 
 define HAL_CAN_POOL_SIZE 6000
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/HitecMosaic/hwdef-bl.dat b/libraries/AP_HAL_ChibiOS/hwdef/HitecMosaic/hwdef-bl.dat
index 08020f6191..655471a41e 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/HitecMosaic/hwdef-bl.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/HitecMosaic/hwdef-bl.dat
@@ -22,7 +22,6 @@ FLASH_SIZE_KB 256
 
 # order of UARTs
 SERIAL_ORDER
-define HAL_USE_UART FALSE
 
 PA6 LED_BOOTLOADER OUTPUT LOW
 define HAL_LED_ON 1
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/f103-periph/hwdef-bl.inc b/libraries/AP_HAL_ChibiOS/hwdef/f103-periph/hwdef-bl.inc
index 84a6b4bc6a..b3920ecaae 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/f103-periph/hwdef-bl.inc
+++ b/libraries/AP_HAL_ChibiOS/hwdef/f103-periph/hwdef-bl.inc
@@ -23,7 +23,6 @@ define CH_CFG_ST_FREQUENCY 1000
 # assume 128k flash part
 FLASH_SIZE_KB 128
 
-define HAL_USE_UART FALSE
 define HAL_USE_SERIAL FALSE
 
 PA4 LED_BOOTLOADER OUTPUT LOW
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/f303-MatekGPS/hwdef-bl.dat b/libraries/AP_HAL_ChibiOS/hwdef/f303-MatekGPS/hwdef-bl.dat
index e61174c663..fc4861ba4c 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/f303-MatekGPS/hwdef-bl.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/f303-MatekGPS/hwdef-bl.dat
@@ -26,7 +26,6 @@ STDOUT_BAUDRATE 57600
 
 # order of UARTs
 SERIAL_ORDER
-define HAL_USE_UART FALSE
 
 PA4 LED_BOOTLOADER OUTPUT LOW
 define HAL_LED_ON 1
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/f303-periph/hwdef-bl.inc b/libraries/AP_HAL_ChibiOS/hwdef/f303-periph/hwdef-bl.inc
index 0ec50db680..b5ca4909e6 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/f303-periph/hwdef-bl.inc
+++ b/libraries/AP_HAL_ChibiOS/hwdef/f303-periph/hwdef-bl.inc
@@ -29,7 +29,6 @@ STDOUT_BAUDRATE 57600
 
 # order of UARTs
 SERIAL_ORDER
-define HAL_USE_UART FALSE
 
 PA4 LED_BOOTLOADER OUTPUT LOW
 define HAL_LED_ON 1