diff --git a/src/include/wchar.h b/src/include/wchar.h
index b590b7a8..026e4cff 100644
--- a/src/include/wchar.h
+++ b/src/include/wchar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: wchar.h,v 1.18 2011/07/03 18:51:01 jsg Exp $	*/
+/*	$OpenBSD: wchar.h,v 1.19 2011/07/04 04:37:34 nicm Exp $	*/
 /*	$NetBSD: wchar.h,v 1.16 2003/03/07 07:11:35 tshiozak Exp $	*/
 
 /*-
@@ -148,6 +148,7 @@ unsigned long int wcstoul(const wchar_t * __restrict, wchar_t ** __restrict,
 		int base);
 
 #if __POSIX_VISIBLE >= 200809
+wchar_t	*wcsdup(const wchar_t *);
 int wcscasecmp(const wchar_t *, const wchar_t *);
 int wcsncasecmp(const wchar_t *, const wchar_t *, size_t);
 #endif
diff --git a/src/lib/libc/string/Makefile.inc b/src/lib/libc/string/Makefile.inc
index 44e011e3..bb285e13 100644
--- a/src/lib/libc/string/Makefile.inc
+++ b/src/lib/libc/string/Makefile.inc
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile.inc,v 1.25 2011/05/28 15:16:46 espie Exp $
+#	$OpenBSD: Makefile.inc,v 1.26 2011/07/04 04:37:34 nicm Exp $
 
 # string sources
 .PATH: ${LIBCSRCDIR}/arch/${MACHINE_CPU}/string ${LIBCSRCDIR}/string
@@ -9,7 +9,7 @@ SRCS+=	bm.c memccpy.c memrchr.c strcasecmp.c strcasestr.c strcoll.c strdup.c \
 	wcscat.c wcschr.c wcscmp.c wcscpy.c wcscspn.c wcslcat.c wcslcpy.c \
 	wcslen.c wcsncat.c wcsncmp.c wcsncpy.c wcspbrk.c wcsrchr.c wcsspn.c \
 	wcsstr.c wcstok.c wcswcs.c wcswidth.c wmemchr.c wmemcmp.c wmemcpy.c \
-	wmemmove.c wmemset.c \
+	wmemmove.c wmemset.c wcsdup.c \
 	timingsafe_bcmp.c wcscasecmp.c
 
 # machine-dependent net sources
@@ -144,7 +144,7 @@ MAN+=	bm.3 bcmp.3 bcopy.3 bstring.3 bzero.3 ffs.3 memccpy.3 memchr.3 \
 	strchr.3 strcmp.3 strcoll.3 strcpy.3 strcspn.3 strerror.3 \
 	string.3 strlen.3 strmode.3 strdup.3 strpbrk.3 strrchr.3 strsep.3 \
 	strsignal.3 strspn.3 strstr.3 strtok.3 strxfrm.3 swab.3 strlcpy.3 \
-	wcstok.3 wmemchr.3 wcswidth.3
+	wcstok.3 wmemchr.3 wcswidth.3 wcsdup.3
 
 MLINKS+=bm.3 bm_comp.3 bm.3 bm_exec.3 bm.3 bm_free.3
 MLINKS+=memchr.3 memrchr.3
diff --git a/src/lib/libc/string/wcsdup.3 b/src/lib/libc/string/wcsdup.3
new file mode 100644
index 00000000..37f82181
--- /dev/null
+++ b/src/lib/libc/string/wcsdup.3
@@ -0,0 +1,86 @@
+.\"	$OpenBSD: wcsdup.3,v 1.1 2011/07/04 04:37:34 nicm Exp $
+.\"	$NetBSD: wcsdup.3,v 1.3 2010/12/16 17:42:28 wiz Exp $
+.\"
+.\" Copyright (c) 1990, 1991, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"     from: @(#)strdup.3	8.1 (Berkeley) 6/9/93
+.\"
+.Dd $Mdocdate: July 4 2011 $
+.Dt WCSDUP 3
+.Os
+.Sh NAME
+.Nm wcsdup
+.Nd save a copy of a string
+.Sh SYNOPSIS
+.In wchar.h
+.Ft wchar_t *
+.Fn wcsdup "const wchar_t *str"
+.Sh DESCRIPTION
+The
+.Fn wcsdup
+function
+allocates sufficient memory for a copy
+of the wide-character string
+.Fa str ,
+does the copy, and returns a pointer to it.
+The pointer may subsequently be used as an
+argument to the function
+.Xr free 3 .
+.Pp
+If insufficient memory is available,
+.Dv NULL
+is returned.
+.Sh EXAMPLES
+The following will point
+.Va p
+to an allocated area of memory containing the nul-terminated string
+.Qq foobar :
+.Bd -literal -offset indent
+wchar_t *p;
+
+if (p = wcsdup(L"foobar"), p == NULL) {
+	fprintf(stderr, "Out of memory.\en");
+	exit(1);
+}
+.Ed
+.Sh ERRORS
+The
+.Fn wcsdup
+function may fail and set the external variable
+.Va errno
+for any of the errors specified for the library function
+.Xr malloc 3 .
+.Sh SEE ALSO
+.Xr free 3 ,
+.Xr malloc 3 ,
+.Xr strdup 3
+.Sh HISTORY
+The
+.Fn wcsdup
+function first appeared in
+.Ox 5.0 .
diff --git a/src/lib/libc/string/wcsdup.c b/src/lib/libc/string/wcsdup.c
new file mode 100644
index 00000000..57a328a8
--- /dev/null
+++ b/src/lib/libc/string/wcsdup.c
@@ -0,0 +1,31 @@
+/*	$OpenBSD: wcsdup.c,v 1.1 2011/07/04 04:37:34 nicm Exp $	*/
+/*	$NetBSD: wcsdup.c,v 1.3 2008/05/26 13:17:48 haad Exp $	*/
+
+/*
+ * Copyright (C) 2006 Aleksey Cheusov
+ *
+ * This material is provided "as is", with absolutely no warranty expressed
+ * or implied. Any use is at your own risk.
+ *
+ * Permission to use or copy this software for any purpose is hereby granted
+ * without fee. Permission to modify the code and to distribute modified
+ * code is also granted without any restrictions.
+ */
+
+#include <stdlib.h>
+#include <wchar.h>
+
+wchar_t *
+wcsdup(const wchar_t *str)
+{
+	wchar_t *copy;
+	size_t len;
+
+	len = wcslen(str) + 1;
+	copy = malloc(len * sizeof (wchar_t));
+
+	if (!copy)
+		return (NULL);
+
+	return (wmemcpy(copy, str, len));
+}