diff --git a/libraries/AP_AHRS/AP_AHRS.h b/libraries/AP_AHRS/AP_AHRS.h
index 149ea5ed61..e64b471bce 100644
--- a/libraries/AP_AHRS/AP_AHRS.h
+++ b/libraries/AP_AHRS/AP_AHRS.h
@@ -31,7 +31,7 @@
 #include <AP_Baro/AP_Baro.h>
 #include <AP_Param/AP_Param.h>
 
-#include "../AP_OpticalFlow/AP_OpticalFlow.h"
+#include <AP_OpticalFlow/AP_OpticalFlow.h>
 
 // Copter defaults to EKF on by default, all others off
 #if APM_BUILD_TYPE(APM_BUILD_ArduCopter)