diff --git a/libraries/AP_Relay/AP_Relay.h b/libraries/AP_Relay/AP_Relay.h
index c1b5a30f10b03b..89c1631f8cb274 100644
--- a/libraries/AP_Relay/AP_Relay.h
+++ b/libraries/AP_Relay/AP_Relay.h
@@ -31,9 +31,6 @@ class AP_Relay {
     // setup the relay pin
     void        init();
 
-    // set relay to state
-    void set(uint8_t instance, bool value);
-
     // activate the relay
     void        on(uint8_t instance) { set(instance, true); }