diff --git a/libraries/AP_AHRS/AP_AHRS.h b/libraries/AP_AHRS/AP_AHRS.h
index 34ac14efcb..6f1fe12c8b 100644
--- a/libraries/AP_AHRS/AP_AHRS.h
+++ b/libraries/AP_AHRS/AP_AHRS.h
@@ -21,7 +21,8 @@
  *
  */
 
-#include <AP_HAL/AP_HAL.h>
+#include <AP_HAL/AP_HAL_Boards.h>
+#include <AP_HAL/Semaphores.h>
 
 #ifndef HAL_NAVEKF2_AVAILABLE
 // only default to EK2 enabled on boards with over 1M flash