--- a/lib/linebuffer.c
+++ b/lib/linebuffer.c
@@ -1,5 +1,5 @@
 /* linebuffer.c -- read arbitrarily long lines
-   Copyright (C) 1986, 1991, 1998, 1999 Free Software Foundation, Inc.
+   Copyright (C) 1986, 1991, 1998, 1999, 2001 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -24,6 +24,7 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include "linebuffer.h"
+#include "unlocked-io.h"
 
 char *xmalloc ();
 char *xrealloc ();