Index: libcfa/src/concurrency/actor.hfa
===================================================================
--- libcfa/src/concurrency/actor.hfa	(revision ce691d20227aa236626a4cb707a44f723beaa254)
+++ libcfa/src/concurrency/actor.hfa	(revision 9d0ff307d494aafc3fc5c8d77da096d4c12b58eb)
@@ -1,5 +1,8 @@
+#pragma once
+
 #include <locks.hfa>
 #include <limits.hfa>
 #include <list.hfa>
+#include <kernel.hfa>
 
 #ifdef __CFA_DEBUG__