diff -up OpenLieroX/src/gusanos/objects_list.h.orig OpenLieroX/src/gusanos/objects_list.h
--- OpenLieroX/src/gusanos/objects_list.h.orig	2012-04-17 02:26:15.000000000 +0200
+++ OpenLieroX/src/gusanos/objects_list.h	2012-04-20 11:20:55.938964194 +0200
@@ -4,6 +4,7 @@
 //#include "game/CGameObject.h"
 #include <list>
 #include <vector>
+#include <unistd.h>
 
 static const int RENDER_LAYERS_AMMOUNT = 10;
 static const int COLLISION_LAYERS_AMMOUNT = 10;