diff --git a/libraries/AP_AHRS/AP_AHRS.cpp b/libraries/AP_AHRS/AP_AHRS.cpp
index 93591c2026..d0985bd803 100644
--- a/libraries/AP_AHRS/AP_AHRS.cpp
+++ b/libraries/AP_AHRS/AP_AHRS.cpp
@@ -39,6 +39,9 @@
 #include <GCS_MAVLink/GCS.h>
 #include <AP_InertialSensor/AP_InertialSensor.h>
 #include <AP_CustomRotations/AP_CustomRotations.h>
+#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
+#include <SITL/SITL.h>
+#endif
 
 #define ATTITUDE_CHECK_THRESH_ROLL_PITCH_RAD radians(10)
 #define ATTITUDE_CHECK_THRESH_YAW_RAD radians(20)