diff --git a/gnu/usr.bin/groff/tmac/mdoc.local b/gnu/usr.bin/groff/tmac/mdoc.local
index bc402af35751..8f4c20e96d47 100644
--- a/gnu/usr.bin/groff/tmac/mdoc.local
+++ b/gnu/usr.bin/groff/tmac/mdoc.local
@@ -1,4 +1,4 @@
-.\" $NetBSD: mdoc.local,v 1.73 2013/03/08 08:29:37 wiz Exp $
+.\" $NetBSD: mdoc.local,v 1.74 2013/09/01 21:14:05 wiz Exp $
 .\"
 .\" Copyright (c) 2003, 2004 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -59,6 +59,7 @@
 .ds doc-operating-system-NetBSD-5.0    5.0
 .ds doc-operating-system-NetBSD-5.1    5.1
 .ds doc-operating-system-NetBSD-6.0    6.0
+.ds doc-operating-system-NetBSD-6.1    6.1
 .ds doc-operating-system-NetBSD-7.0    7.0
 .ds doc-operating-system-FreeBSD-4.11  4.11
 .ds doc-operating-system-FreeBSD-5.4   5.4