diff --git a/libraries/AP_HAL_ChibiOS/hwdef/BlitzH743Pro/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/BlitzH743Pro/hwdef.dat
index 9d5d308713a..32a5fb37182 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/BlitzH743Pro/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/BlitzH743Pro/hwdef.dat
@@ -90,12 +90,12 @@ PE1 UART8_TX UART8 NODMA
 # I2C ports
 I2C_ORDER I2C1 I2C2
 # I2C1
-PB6 I2C1_SCL I2C1
-PB7 I2C1_SDA I2C1
+PB6 I2C1_SCL I2C1 PULLUP
+PB7 I2C1_SDA I2C1 PULLUP
 
 # I2C2
-PB10 I2C2_SCL I2C2
-PB11 I2C2_SDA I2C2
+PB10 I2C2_SCL I2C2 PULLUP
+PB11 I2C2_SDA I2C2 PULLUP
 
 # microSD support
 PC8 SDMMC1_D0 SDMMC1