diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/board.c b/libraries/AP_HAL_ChibiOS/hwdef/common/board.c
index 21b451fb5a..59d3404ce5 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/board.c
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/board.c
@@ -169,8 +169,13 @@ static void stm32_gpio_init(void) {
 
   /* Enabling GPIO-related clocks, the mask comes from the
      registry header file.*/
+#if defined(STM32H7)
+  rccResetAHB4(STM32_GPIO_EN_MASK);
+  rccEnableAHB4(STM32_GPIO_EN_MASK, true);
+#else
   rccResetAHB1(STM32_GPIO_EN_MASK);
   rccEnableAHB1(STM32_GPIO_EN_MASK, true);
+#endif
 
   /* Initializing all the defined GPIO ports.*/
 #if STM32_HAS_GPIOA
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32H743xx.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32H743xx.py
index cb3af07a8a..845a515c8e 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32H743xx.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32H743xx.py
@@ -37,8 +37,8 @@ pincount = {
     'G': 16,
     'H': 16,
     'I': 16,
-    'J': 0,
-    'K': 0
+    'J': 16,
+    'K': 16
 }
     
 # no DMA map as we will dynamically allocate DMA channels using the DMAMUX