diff --git a/contrib/sdk/sources/newlib/libc/Tupfile.lua b/contrib/sdk/sources/newlib/libc/Tupfile.lua
index f91d56c96a..a215f40ebe 100644
--- a/contrib/sdk/sources/newlib/libc/Tupfile.lua
+++ b/contrib/sdk/sources/newlib/libc/Tupfile.lua
@@ -385,7 +385,6 @@ STDIO_SRCS = {
   "iprintf.c",
   "iscanf.c",
   "makebuf.c",
-  "mbstowcs.c",
   "mktemp.c",
   "open_memstream.c",
   "perror.c",
diff --git a/contrib/sdk/sources/newlib/libc/stdio/mbstowcs.c b/contrib/sdk/sources/newlib/libc/stdio/mbstowcs.c
deleted file mode 100644
index 09543451cf..0000000000
--- a/contrib/sdk/sources/newlib/libc/stdio/mbstowcs.c
+++ /dev/null
@@ -1,83 +0,0 @@
-/*
-FUNCTION
-<<mbstowcs>>---minimal multibyte string to wide char converter
-
-INDEX
-	mbstowcs
-
-ANSI_SYNOPSIS
-	#include <stdlib.h>
-	int mbstowcs(wchar_t *restrict <[pwc]>, const char *restrict <[s]>, size_t <[n]>);
-
-TRAD_SYNOPSIS
-	#include <stdlib.h>
-	int mbstowcs(<[pwc]>, <[s]>, <[n]>)
-	wchar_t *<[pwc]>;
-	const char *<[s]>;
-	size_t <[n]>;
-
-DESCRIPTION
-When _MB_CAPABLE is not defined, this is a minimal ANSI-conforming 
-implementation of <<mbstowcs>>.  In this case, the
-only ``multi-byte character sequences'' recognized are single bytes,
-and they are ``converted'' to wide-char versions simply by byte
-extension.
-
-When _MB_CAPABLE is defined, this routine calls <<_mbstowcs_r>> to perform
-the conversion, passing a state variable to allow state dependent
-decoding.  The result is based on the locale setting which may
-be restricted to a defined set of locales.
-
-RETURNS
-This implementation of <<mbstowcs>> returns <<0>> if
-<[s]> is <<NULL>> or is the empty string; 
-it returns <<-1>> if _MB_CAPABLE and one of the
-multi-byte characters is invalid or incomplete;
-otherwise it returns the minimum of: <<n>> or the
-number of multi-byte characters in <<s>> plus 1 (to
-compensate for the nul character).
-If the return value is -1, the state of the <<pwc>> string is
-indeterminate.  If the input has a length of 0, the output
-string will be modified to contain a wchar_t nul terminator.
-
-PORTABILITY
-<<mbstowcs>> is required in the ANSI C standard.  However, the precise
-effects vary with the locale.
-
-<<mbstowcs>> requires no supporting OS subroutines.
-*/
-
-#ifndef _REENT_ONLY
-
-#include <newlib.h>
-#include <stdlib.h>
-#include <wchar.h>
-
-size_t
-_DEFUN (mbstowcs, (pwcs, s, n),
-        wchar_t *__restrict pwcs _AND
-        const char *__restrict s _AND
-        size_t n)
-{
-#ifdef _MB_CAPABLE
-  mbstate_t state;
-  state.__count = 0;
-  
-  return _mbstowcs_r (_REENT, pwcs, s, n, &state);
-#else /* not _MB_CAPABLE */
-  
-  int count = 0;
-  
-  if (n != 0) {
-    do {
-      if ((*pwcs++ = (wchar_t) *s++) == 0)
-	break;
-      count++;
-    } while (--n != 0);
-  }
-  
-  return count;
-#endif /* not _MB_CAPABLE */
-}
-
-#endif /* !_REENT_ONLY */