diff --git a/libc/wchar/wcsncat.c b/libc/wchar/wcsncat.c
new file mode 100644
index 0000000..44f1ff9
--- /dev/null
+++ b/libc/wchar/wcsncat.c
@@ -0,0 +1,57 @@
+/*-
+ * Copyright (c)1999 Citrus Project,
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ *	citrus Id: wcsncat.c,v 1.1 1999/12/29 21:47:45 tshiozak Exp
+ */
+
+#include <sys/cdefs.h>
+#if 0
+#if defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: wcsncat.c,v 1.1 2000/12/23 23:14:36 itojun Exp $");
+#endif /* LIBC_SCCS and not lint */
+#endif
+__FBSDID("$FreeBSD$");
+
+#include <wchar.h>
+
+wchar_t *
+wcsncat(wchar_t * __restrict s1, const wchar_t * __restrict s2, size_t n)
+{
+	wchar_t *p;
+	wchar_t *q;
+	const wchar_t *r;
+
+	p = s1;
+	while (*p)
+		p++;
+	q = p;
+	r = s2;
+	while (*r && n) {
+		*q++ = *r++;
+		n--;
+	}
+	*q = '\0';
+	return s1;
+}