diff --git a/libc/Android.mk b/libc/Android.mk
index ff21d6a..9b71f6a 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -223,7 +223,6 @@
     upstream-freebsd/lib/libc/stdio/fclose.c \
     upstream-freebsd/lib/libc/stdio/flags.c \
     upstream-freebsd/lib/libc/stdio/fopen.c \
-    upstream-freebsd/lib/libc/stdio/fwrite.c \
     upstream-freebsd/lib/libc/stdio/makebuf.c \
     upstream-freebsd/lib/libc/stdio/mktemp.c \
     upstream-freebsd/lib/libc/stdio/setvbuf.c \
@@ -388,6 +387,7 @@
     upstream-openbsd/lib/libc/stdio/fwalk.c \
     upstream-openbsd/lib/libc/stdio/fwide.c \
     upstream-openbsd/lib/libc/stdio/fwprintf.c \
+    upstream-openbsd/lib/libc/stdio/fwrite.c \
     upstream-openbsd/lib/libc/stdio/fwscanf.c \
     upstream-openbsd/lib/libc/stdio/getc.c \
     upstream-openbsd/lib/libc/stdio/getchar.c \
diff --git a/libc/stdio/fvwrite.h b/libc/upstream-openbsd/lib/libc/stdio/fvwrite.h
similarity index 93%
rename from libc/stdio/fvwrite.h
rename to libc/upstream-openbsd/lib/libc/stdio/fvwrite.h
index 96f65de..d3a309b 100644
--- a/libc/stdio/fvwrite.h
+++ b/libc/upstream-openbsd/lib/libc/stdio/fvwrite.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fvwrite.h,v 1.5 2003/06/02 20:18:37 millert Exp $	*/
+/*	$OpenBSD: fvwrite.h,v 1.6 2013/11/12 07:04:35 deraadt Exp $	*/
 
 /*-
  * Copyright (c) 1990, 1993
@@ -36,7 +36,7 @@
  * I/O descriptors for __sfvwrite().
  */
 struct __siov {
-	const void	*iov_base;
+	void	*iov_base;
 	size_t	iov_len;
 };
 struct __suio {
@@ -46,3 +46,4 @@
 };
 
 extern int __sfvwrite(FILE *, struct __suio *);
+wint_t __fputwc_unlock(wchar_t wc, FILE *fp);
diff --git a/libc/upstream-freebsd/lib/libc/stdio/fwrite.c b/libc/upstream-openbsd/lib/libc/stdio/fwrite.c
similarity index 74%
rename from libc/upstream-freebsd/lib/libc/stdio/fwrite.c
rename to libc/upstream-openbsd/lib/libc/stdio/fwrite.c
index 707d362..f0a17bf 100644
--- a/libc/upstream-freebsd/lib/libc/stdio/fwrite.c
+++ b/libc/upstream-openbsd/lib/libc/stdio/fwrite.c
@@ -1,3 +1,4 @@
+/*	$OpenBSD: fwrite.c,v 1.11 2014/05/01 16:40:36 deraadt Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -30,67 +31,58 @@
  * SUCH DAMAGE.
  */
 
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)fwrite.c	8.1 (Berkeley) 6/4/93";
-#endif /* LIBC_SCCS and not lint */
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
-#include "namespace.h"
-#include <errno.h>
-#include <stdint.h>
 #include <stdio.h>
-#include "un-namespace.h"
+#include <stdlib.h>
+#include <stdint.h>
+#include <errno.h>
 #include "local.h"
 #include "fvwrite.h"
-#include "libc_private.h"
+
+#define MUL_NO_OVERFLOW	(1UL << (sizeof(size_t) * 4))
 
 /*
  * Write `count' objects (each size `size') from memory to the given file.
  * Return the number of whole objects written.
  */
 size_t
-fwrite(const void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)
+fwrite(const void *buf, size_t size, size_t count, FILE *fp)
 {
 	size_t n;
 	struct __suio uio;
 	struct __siov iov;
+	int ret;
 
 	/*
-	 * ANSI and SUSv2 require a return value of 0 if size or count are 0.
+	 * Extension:  Catch integer overflow
 	 */
-	if ((count == 0) || (size == 0))
-		return (0);
-
-	/*
-	 * Check for integer overflow.  As an optimization, first check that
-	 * at least one of {count, size} is at least 2^16, since if both
-	 * values are less than that, their product can't possible overflow
-	 * (size_t is always at least 32 bits on FreeBSD).
-	 */
-	if (((count | size) > 0xFFFF) &&
-	    (count > SIZE_MAX / size)) {
-		errno = EINVAL;
+	if ((size >= MUL_NO_OVERFLOW || count >= MUL_NO_OVERFLOW) &&
+	    size > 0 && SIZE_MAX / size < count) {
+		errno = EOVERFLOW;
 		fp->_flags |= __SERR;
 		return (0);
 	}
 
-	n = count * size;
+	/*
+	 * ANSI and SUSv2 require a return value of 0 if size or count are 0.
+	 */
+	if ((n = count * size) == 0)
+		return (0);
 
 	iov.iov_base = (void *)buf;
 	uio.uio_resid = iov.iov_len = n;
 	uio.uio_iov = &iov;
 	uio.uio_iovcnt = 1;
 
-	FLOCKFILE(fp);
-	ORIENT(fp, -1);
 	/*
 	 * The usual case is success (__sfvwrite returns 0);
 	 * skip the divide if this happens, since divides are
 	 * generally slow and since this occurs whenever size==0.
 	 */
-	if (__sfvwrite(fp, &uio) != 0)
-	    count = (n - uio.uio_resid) / size;
+	FLOCKFILE(fp);
+	_SET_ORIENTATION(fp, -1);
+	ret = __sfvwrite(fp, &uio);
 	FUNLOCKFILE(fp);
-	return (count);
+	if (ret == 0)
+		return (count);
+	return ((n - uio.uio_resid) / size);
 }