diff --git a/lisp/os-common.c b/lisp/os-common.c
index e1f90ba9be7a0c44c99072ef4326309b16e73a5e..822ea3e44aaf4268a78301a75e8a0e9dce16f8fc 100644
--- a/lisp/os-common.c
+++ b/lisp/os-common.c
@@ -1,12 +1,13 @@
 /*
 
- $Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/lisp/os-common.c,v 1.23 2007/07/31 10:08:47 cshapiro Exp $
+ $Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/lisp/os-common.c,v 1.24 2007/07/31 11:50:17 cshapiro Exp $
 
  This code was written as part of the CMU Common Lisp project at
  Carnegie Mellon University, and has been placed in the public domain.
 
 */
 
+#include <errno.h>
 #include <stdio.h>
 #include <string.h>