diff --git a/pmc/include/cube.h b/pmc/include/cube.h
--- a/pmc/include/cube.h
+++ b/pmc/include/cube.h
@@ -16,7 +16,7 @@
     int height;
 
   public:
-    Cube (Surface *, Vector, Vector, Vector, Vector, int);
+    Cube (Surface *, Vector&, Vector&, Vector&, Vector&, int);
     Cube (Surface *);
 
     virtual ~ Cube ();