diff --git a/libraries/AP_HAL_ChibiOS/GPIO.cpp b/libraries/AP_HAL_ChibiOS/GPIO.cpp
index 3e6d2e0516e..1805e083e8f 100644
--- a/libraries/AP_HAL_ChibiOS/GPIO.cpp
+++ b/libraries/AP_HAL_ChibiOS/GPIO.cpp
@@ -78,11 +78,6 @@ void GPIO::pinMode(uint8_t pin, uint8_t output)
     }
 }
 
-int8_t GPIO::analogPinToDigitalPin(uint8_t pin)
-{
-    return -1;
-}
-
 
 uint8_t GPIO::read(uint8_t pin)
 {
diff --git a/libraries/AP_HAL_ChibiOS/GPIO.h b/libraries/AP_HAL_ChibiOS/GPIO.h
index 6fdd3f6f19f..b95aee97d8a 100644
--- a/libraries/AP_HAL_ChibiOS/GPIO.h
+++ b/libraries/AP_HAL_ChibiOS/GPIO.h
@@ -31,7 +31,6 @@ public:
     GPIO();
     void    init();
     void    pinMode(uint8_t pin, uint8_t output);
-    int8_t  analogPinToDigitalPin(uint8_t pin);
     uint8_t read(uint8_t pin);
     void    write(uint8_t pin, uint8_t value);
     void    toggle(uint8_t pin);