diff --git a/libc/Android.mk b/libc/Android.mk
index 5cadba1..90b0d4e 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -246,7 +246,6 @@
     upstream-freebsd/lib/libc/string/wcsnlen.c \
     upstream-freebsd/lib/libc/string/wcspbrk.c \
     upstream-freebsd/lib/libc/string/wcsspn.c \
-    upstream-freebsd/lib/libc/string/wcsstr.c \
     upstream-freebsd/lib/libc/string/wcstok.c \
     upstream-freebsd/lib/libc/string/wmemchr.c \
     upstream-freebsd/lib/libc/string/wmemcpy.c \
@@ -419,6 +418,8 @@
     upstream-openbsd/lib/libc/string/strstr.c \
     upstream-openbsd/lib/libc/string/strtok.c \
     upstream-openbsd/lib/libc/string/wcslcpy.c \
+    upstream-openbsd/lib/libc/string/wcsstr.c \
+    upstream-openbsd/lib/libc/string/wcswcs.c \
     upstream-openbsd/lib/libc/string/wcswidth.c \
 
 libc_arch_static_src_files := \
diff --git a/libc/bionic/wchar.cpp b/libc/bionic/wchar.cpp
index 021d14b..f921aa0 100644
--- a/libc/bionic/wchar.cpp
+++ b/libc/bionic/wchar.cpp
@@ -296,12 +296,6 @@
   return strtoul(reinterpret_cast<const char*>(nptr), reinterpret_cast<char**>(endptr), base);
 }
 
-wchar_t* wcswcs(const wchar_t* ws1, const wchar_t* ws2) {
-  const char* s1 = reinterpret_cast<const char*>(ws1);
-  const char* s2 = reinterpret_cast<const char*>(ws2);
-  return reinterpret_cast<wchar_t*>(strstr(s1, s2));
-}
-
 int wctob(wint_t c) {
   return c;
 }
diff --git a/libc/upstream-freebsd/lib/libc/string/wcsstr.c b/libc/upstream-freebsd/lib/libc/string/wcsstr.c
deleted file mode 100644
index ce598a6..0000000
--- a/libc/upstream-freebsd/lib/libc/string/wcsstr.c
+++ /dev/null
@@ -1,63 +0,0 @@
-/*-
- * Copyright (c) 1990, 1993
- *	The Regents of the University of California.  All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Chris Torek.
- *
- * 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.
- */
-
-#if 0
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)strstr.c	8.1 (Berkeley) 6/4/93";
-#endif /* LIBC_SCCS and not lint */
-#endif
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
-#include <wchar.h>
-
-/*
- * Find the first occurrence of find in s.
- */
-wchar_t *
-wcsstr(const wchar_t * __restrict s, const wchar_t * __restrict find)
-{
-	wchar_t c, sc;
-	size_t len;
-
-	if ((c = *find++) != L'\0') {
-		len = wcslen(find);
-		do {
-			do {
-				if ((sc = *s++) == L'\0')
-					return (NULL);
-			} while (sc != c);
-		} while (wcsncmp(s, find, len) != 0);
-		s--;
-	}
-	return ((wchar_t *)s);
-}
diff --git a/libc/upstream-openbsd/lib/libc/string/wcsstr.c b/libc/upstream-openbsd/lib/libc/string/wcsstr.c
new file mode 100644
index 0000000..669e340
--- /dev/null
+++ b/libc/upstream-openbsd/lib/libc/string/wcsstr.c
@@ -0,0 +1,70 @@
+/*	$OpenBSD: wcsstr.c,v 1.3 2005/08/08 08:05:37 espie Exp $	*/
+/*	$NetBSD: wcsstr.c,v 1.3 2003/03/05 20:18:17 tshiozak Exp $	*/
+
+/*-
+ * 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: wcsstr.c,v 1.2 2000/12/21 05:07:25 itojun Exp
+ */
+
+#include <wchar.h>
+
+wchar_t *
+#ifdef WCSWCS
+wcswcs(const wchar_t *big, const wchar_t *little)
+#else
+wcsstr(const wchar_t *big, const wchar_t *little)
+#endif
+{
+	const wchar_t *p;
+	const wchar_t *q;
+	const wchar_t *r;
+
+	if (!*little) {
+		/* LINTED interface specification */
+		return (wchar_t *)big;
+	}
+	if (wcslen(big) < wcslen(little))
+		return NULL;
+
+	p = big;
+	q = little;
+	while (*p) {
+		q = little;
+		r = p;
+		while (*q) {
+			if (*r != *q)
+				break;
+			q++;
+			r++;
+		}
+		if (!*q) {
+			/* LINTED interface specification */
+			return (wchar_t *)p;
+		}
+		p++;
+	}
+	return NULL;
+}
diff --git a/libc/upstream-openbsd/lib/libc/string/wcswcs.c b/libc/upstream-openbsd/lib/libc/string/wcswcs.c
new file mode 100644
index 0000000..bd35605
--- /dev/null
+++ b/libc/upstream-openbsd/lib/libc/string/wcswcs.c
@@ -0,0 +1,5 @@
+/*	$OpenBSD: wcswcs.c,v 1.1 2005/04/13 16:35:58 espie Exp $	*/
+/* $NetBSD: wcswcs.c,v 1.1 2003/03/05 20:18:17 tshiozak Exp $ */
+
+#define WCSWCS
+#include "wcsstr.c"
diff --git a/tests/wchar_test.cpp b/tests/wchar_test.cpp
index be451c1..eff845a 100644
--- a/tests/wchar_test.cpp
+++ b/tests/wchar_test.cpp
@@ -159,3 +159,18 @@
 TEST(wchar, limits) {
   ASSERT_LT(WCHAR_MIN, WCHAR_MAX);
 }
+
+TEST(wchar, wcsstr_wcswcs) {
+  const wchar_t* haystack = L"matches hello world, not the second hello world";
+  const wchar_t* empty_needle = L"";
+  const wchar_t* good_needle = L"ll";
+  const wchar_t* bad_needle = L"wort";
+
+  ASSERT_EQ(haystack, wcsstr(haystack, empty_needle));
+  ASSERT_EQ(&haystack[10], wcsstr(haystack, good_needle));
+  ASSERT_EQ(NULL, wcsstr(haystack, bad_needle));
+
+  ASSERT_EQ(haystack, wcswcs(haystack, empty_needle));
+  ASSERT_EQ(&haystack[10], wcswcs(haystack, good_needle));
+  ASSERT_EQ(NULL, wcswcs(haystack, bad_needle));
+}