diff --git a/libraries/APM_Control/AP_AutoTune.cpp b/libraries/APM_Control/AP_AutoTune.cpp
index 64d5fab2ee..24a8611bac 100644
--- a/libraries/APM_Control/AP_AutoTune.cpp
+++ b/libraries/APM_Control/AP_AutoTune.cpp
@@ -28,6 +28,7 @@
 #include <AC_PID/AC_PID.h>
 #include <AP_Scheduler/AP_Scheduler.h>
 #include <GCS_MAVLink/GCS.h>
+#include <AP_InertialSensor/AP_InertialSensor.h>
 
 extern const AP_HAL::HAL& hal;