diff --git a/targets/CMSIS-OS/ChibiOS/Include/targetPAL.h b/targets/CMSIS-OS/ChibiOS/Include/targetPAL.h
index 271ad5e63a..23917484ca 100644
--- a/targets/CMSIS-OS/ChibiOS/Include/targetPAL.h
+++ b/targets/CMSIS-OS/ChibiOS/Include/targetPAL.h
@@ -3,16 +3,20 @@
 // See LICENSE file in the project root for full license information.
 //
 
-#ifndef _GPIO_PORT
-#define _GPIO_PORT
+#ifndef _TARGETPAL_H_
+#define _TARGETPAL_H_
 
 #include <hal.h>
 
 
+#if defined(STM32F0XX) || defined(STM32F4XX) || defined(STM32F7XX) || defined(STM32H7XX)
+
 // Contains available GPIO ports for the current board
 extern stm32_gpio_t* gpioPort[];
 
 //Gets the GPIO according to a pin number
 #define GPIO_PORT(pin) (gpioPort[pin/16])
 
-#endif
+#endif // defined(STM32F0xx) || defined(STM32F4xx) || defined(STM32F7xx) || defined(STM32H7xx)
+
+#endif // _TARGETPAL_H_
diff --git a/targets/CMSIS-OS/ChibiOS/nanoCLR/targetPAL.c b/targets/CMSIS-OS/ChibiOS/nanoCLR/targetPAL.c
index 9cff098439..3f0c44df01 100644
--- a/targets/CMSIS-OS/ChibiOS/nanoCLR/targetPAL.c
+++ b/targets/CMSIS-OS/ChibiOS/nanoCLR/targetPAL.c
@@ -5,6 +5,8 @@
 
 #include <hal.h>
 
+#if defined(STM32F0XX) || defined(STM32F4XX) || defined(STM32F7XX) || defined(STM32H7XX)
+
 stm32_gpio_t* gpioPort[] = { GPIOA, GPIOB
 #if STM32_HAS_GPIOC
 , GPIOC
@@ -34,3 +36,5 @@ stm32_gpio_t* gpioPort[] = { GPIOA, GPIOB
 , GPIOK
 #endif
 };
+
+#endif // defined(STM32F0xx) || defined(STM32F4xx) || defined(STM32F7xx) || defined(STM32H7xx)
diff --git a/targets/FreeRTOS/ESP32_DevKitC/Include/targetPAL.h b/targets/FreeRTOS/ESP32_DevKitC/Include/targetPAL.h
index c0ed853425..42d1f49456 100644
--- a/targets/FreeRTOS/ESP32_DevKitC/Include/targetPAL.h
+++ b/targets/FreeRTOS/ESP32_DevKitC/Include/targetPAL.h
@@ -3,9 +3,9 @@
 // See LICENSE file in the project root for full license information.
 //
 
-#ifndef _GPIO_PORT
-#define _GPIO_PORT
+#ifndef _TARGETPAL_H_
+#define _TARGETPAL_H_
 
 
 
-#endif
+#endif // _TARGETPAL_H_