diff --git a/libraries/AP_Relay/AP_Relay.cpp b/libraries/AP_Relay/AP_Relay.cpp
index 33c1a2d48e..607a8e5fbb 100644
--- a/libraries/AP_Relay/AP_Relay.cpp
+++ b/libraries/AP_Relay/AP_Relay.cpp
@@ -12,6 +12,7 @@
 #include "AP_Relay.h"
 
 #include <AP_HAL/AP_HAL.h>
+#include <AP_Math/AP_Math.h>
 #include <GCS_MAVLink/GCS.h>
 #include <AP_Logger/AP_Logger.h>
 
diff --git a/libraries/AP_Relay/AP_Relay.h b/libraries/AP_Relay/AP_Relay.h
index fa4bcfc9dd..40e2af62c1 100644
--- a/libraries/AP_Relay/AP_Relay.h
+++ b/libraries/AP_Relay/AP_Relay.h
@@ -15,7 +15,6 @@
 
 #include <AP_Param/AP_Param.h>
 #include <AP_Relay/AP_Relay_Params.h>
-#include <AP_Common/Bitmask.h>
 
 #ifndef AP_RELAY_NUM_RELAYS
   #define AP_RELAY_NUM_RELAYS 6
diff --git a/libraries/AP_Relay/AP_Relay_Params.h b/libraries/AP_Relay/AP_Relay_Params.h
index c8c9f7ab98..9b6a9d1cc5 100644
--- a/libraries/AP_Relay/AP_Relay_Params.h
+++ b/libraries/AP_Relay/AP_Relay_Params.h
@@ -1,7 +1,6 @@
 #pragma once
 
 #include <AP_Param/AP_Param.h>
-#include "AP_Relay_config.h"
 
 class AP_Relay_Params {
 public: