diff -ru late-0.1.0.orig/src/ball.h late-0.1.0/src/ball.h
--- late-0.1.0.orig/src/ball.h	2003-08-07 18:26:13.000000000 -0400
+++ late-0.1.0/src/ball.h	2011-04-07 21:32:14.189799689 -0400
@@ -25,6 +25,7 @@
 class ball;
 
 #include "square.h"
+#include <cstddef>
 
 class ball_base
 {