--- a/main.c	1995-08-11 02:00:00.000000000 +0200
+++ b/main.c	2010-08-26 23:57:03.000000000 +0200
@@ -91,6 +91,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <string.h>
 #include <ctype.h>
 #include "pep.h"