diff --git a/libraries/AP_Compass/Compass_PerMotor.cpp b/libraries/AP_Compass/Compass_PerMotor.cpp
index bd0985a020..cae61c707d 100644
--- a/libraries/AP_Compass/Compass_PerMotor.cpp
+++ b/libraries/AP_Compass/Compass_PerMotor.cpp
@@ -4,6 +4,7 @@
 
 #include "AP_Compass.h"
 #include <GCS_MAVLink/GCS.h>
+#include <SRV_Channel/SRV_Channel.h>
 
 extern const AP_HAL::HAL &hal;