--- texk/lacheck/lacheck-1.26/lacheck.l
+++ texk/lacheck/lacheck-1.26/lacheck.l	2008-03-05 13:59:37.000000000 +0000
@@ -117,6 +117,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <unistd.h>
 
 #if defined(WIN32) && !defined(__MINGW32__)
 #include <win32lib.h>