diff --git a/libraries/AP_HAL_ChibiOS/hwdef/F4BY/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/F4BY/hwdef.dat
index ea5ecf6cfa..3e5ba8bded 100755
--- a/libraries/AP_HAL_ChibiOS/hwdef/F4BY/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/F4BY/hwdef.dat
@@ -106,8 +106,6 @@ define HAL_OS_FATFS_IO 1
 # now some defines for logging and terrain data files
 define HAL_BOARD_LOG_DIRECTORY "/APM/LOGS"
 define HAL_BOARD_TERRAIN_DIRECTORY "/APM/TERRAIN"
-define HAL_DATAFLASH_FILE_BUFSIZE 8
-define HAL_DATAFLASH_MAV_BUFSIZE 2
 
 # this defines the default maximum clock on I2C devices.
 define HAL_I2C_MAX_CLOCK 100000
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/MatekF405-Wing/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/MatekF405-Wing/hwdef.dat
index 2f1950b043..875b039f8f 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/MatekF405-Wing/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/MatekF405-Wing/hwdef.dat
@@ -156,8 +156,6 @@ define HAL_INS_DEFAULT_ROTATION ROTATION_YAW_180
 define HAL_OS_FATFS_IO 1
 define HAL_BOARD_LOG_DIRECTORY "/APM/LOGS"
 define HAL_BOARD_TERRAIN_DIRECTORY "/APM/TERRAIN"
-define HAL_DATAFLASH_FILE_BUFSIZE 8
-define HAL_DATAFLASH_MAV_BUFSIZE 2
 
 # define default battery setup
 define HAL_BATT_VOLT_PIN 10
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/MatekF405/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/MatekF405/hwdef.dat
index e5381b25d1..ece4920879 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/MatekF405/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/MatekF405/hwdef.dat
@@ -157,8 +157,6 @@ SPIDEV osd       SPI2 DEVID1 MAX7456_CS MODE0 10*MHZ 10*MHZ
 define HAL_OS_FATFS_IO 1
 define HAL_BOARD_LOG_DIRECTORY "/APM/LOGS"
 define HAL_BOARD_TERRAIN_DIRECTORY "/APM/TERRAIN"
-define HAL_DATAFLASH_FILE_BUFSIZE 8
-define HAL_DATAFLASH_MAV_BUFSIZE 2
 
 # 8 PWM available by default
 define BOARD_PWM_COUNT_DEFAULT 8
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/omnibusf4pro/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/omnibusf4pro/hwdef.dat
index 2848936c8e..992827d368 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/omnibusf4pro/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/omnibusf4pro/hwdef.dat
@@ -114,8 +114,6 @@ define HAL_STORAGE_SIZE 15360
 define HAL_OS_FATFS_IO 1
 define HAL_BOARD_LOG_DIRECTORY "/APM/LOGS"
 define HAL_BOARD_TERRAIN_DIRECTORY "/APM/TERRAIN"
-define HAL_DATAFLASH_FILE_BUFSIZE 8
-define HAL_DATAFLASH_MAV_BUFSIZE 2
 
 # define default battery setup
 define HAL_BATT_VOLT_PIN 12