Index: libcfa/src/concurrency/actor.hfa
===================================================================
--- libcfa/src/concurrency/actor.hfa	(revision c042d79052e8b85f87eb194140ecd13bd3edae58)
+++ libcfa/src/concurrency/actor.hfa	(revision a8e8c679fcf2fe80dcd5836b55b5688ff240d812)
@@ -1,5 +1,8 @@
+#pragma once
+
 #include <locks.hfa>
 #include <limits.hfa>
 #include <list.hfa>
+#include <kernel.hfa>
 
 #ifdef __CFA_DEBUG__