diff --git a/libraries/AP_HAL_ChibiOS/GPIO.h b/libraries/AP_HAL_ChibiOS/GPIO.h
index d467f1f0fd..d149ef2801 100644
--- a/libraries/AP_HAL_ChibiOS/GPIO.h
+++ b/libraries/AP_HAL_ChibiOS/GPIO.h
@@ -22,10 +22,12 @@
 #define HAL_GPIO_LED_ON 0
 #endif
 
-#ifndef HAL_GPIO_LED_OFF
-#define HAL_GPIO_LED_OFF 1
+#ifdef HAL_GPIO_LED_OFF
+#error "HAL_GPIO_LED_OFF must not be defined, it is implicitly !HAL_GPIO_LED_ON"
 #endif
 
+#define HAL_GPIO_LED_OFF (!HAL_GPIO_LED_ON)
+
 /*
   pin types for alternative configuration
  */