diff --git a/include/__locale b/include/__locale
index b2cbd382..8aa8fc1f 100644
--- a/include/__locale
+++ b/include/__locale
@@ -20,7 +20,7 @@
 #include <cctype>
 #include <locale.h>
 #if _WIN32
-# include <support/win32/locale.h>
+# include <support/win32/locale_win32.h>
 #else  // _WIN32
 # include <xlocale.h>
 #endif  // _WIN32
diff --git a/include/locale b/include/locale
index c0b5f9e7..9f9996a0 100644
--- a/include/locale
+++ b/include/locale
@@ -187,8 +187,7 @@ template <class charT> class messages_byname;
 #include <cstdlib>
 #include <ctime>
 #if _WIN32
-#include <support/win32/support.h>
-#include <support/win32/locale.h>
+#include <support/win32/locale_win32.h>
 #else // _WIN32
 #include <nl_types.h>
 #endif  // !_WIN32
diff --git a/include/support/win32/locale.h b/include/support/win32/locale_win32.h
similarity index 95%
rename from include/support/win32/locale.h
rename to include/support/win32/locale_win32.h
index d640be13..8b7267c1 100644
--- a/include/support/win32/locale.h
+++ b/include/support/win32/locale_win32.h
@@ -1,5 +1,5 @@
 // -*- C++ -*-
-//===------------------------ support/win32/locale.h ----------------------===//
+//===--------------------- support/win32/locale_win32.h -------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -8,8 +8,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef _LIBCPP_SUPPORT_WIN32_LOCALE_H
-#define _LIBCPP_SUPPORT_WIN32_LOCALE_H
+#ifndef _LIBCPP_SUPPORT_WIN32_LOCALE_WIN32_H
+#define _LIBCPP_SUPPORT_WIN32_LOCALE_WIN32_H
 
 // ctype mask table defined in msvcrt.dll
 extern "C" unsigned short  __declspec(dllimport) _ctype[];
@@ -107,4 +107,4 @@ inline int iswblank_l( wint_t c, locale_t /*loc*/ )
     return ( c == L' ' || c == L'\t' );
 }
 
-#endif // _LIBCPP_SUPPORT_WIN32_LOCALE_H
\ No newline at end of file
+#endif // _LIBCPP_SUPPORT_WIN32_LOCALE_WIN32_H
diff --git a/src/locale.cpp b/src/locale.cpp
index f303e8fb..c75a1542 100644
--- a/src/locale.cpp
+++ b/src/locale.cpp
@@ -20,7 +20,7 @@
 #include "cwctype"
 #include "__sso_allocator"
 #if _WIN32
-#include <support/win32/locale.h>
+#include <support/win32/locale_win32.h>
 #else // _WIN32
 #include <langinfo.h>
 #endif // _!WIN32
diff --git a/src/support/win32/locale_win32.cpp b/src/support/win32/locale_win32.cpp
new file mode 100644
index 00000000..07cd392c
--- /dev/null
+++ b/src/support/win32/locale_win32.cpp
@@ -0,0 +1,94 @@
+// -*- C++ -*-
+//===-------------------- support/win32/locale_win32.cpp ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "support/win32/locale_win32.h"
+
+#include <stdarg.h> // va_start, va_end
+
+// FIXME: base currently unused. Needs manual work to construct the new locale
+locale_t newlocale( int mask, const char * locale, locale_t /*base*/ )
+{
+    return _create_locale( mask, locale );
+}
+locale_t uselocale( locale_t newloc )
+{
+    locale_t old_locale = _get_current_locale();
+    // uselocale sets the thread's locale by definition, so unconditionally use thread-local locale
+    _configthreadlocale( _ENABLE_PER_THREAD_LOCALE );
+	// uselocale sets all categories
+	setlocale( LC_ALL, newloc->locinfo->lc_category[LC_ALL].locale );
+	// uselocale returns the old locale_t
+	return old_locale;
+}
+lconv *localeconv_l( locale_t loc )
+{
+    __locale_raii __current( uselocale(loc), uselocale );
+    return localeconv();
+}
+size_t mbrlen_l( const char *__restrict__ s, size_t n,
+                 mbstate_t *__restrict__ ps, locale_t loc )
+{
+    __locale_raii __current( uselocale(loc), uselocale );
+    return mbrlen( s, n, ps );
+}
+size_t mbsrtowcs_l( wchar_t *__restrict__ dst, const char **__restrict__ src,
+                    size_t len, mbstate_t *__restrict__ ps, locale_t loc )
+{
+    __locale_raii __current( uselocale(loc), uselocale );
+    return mbsrtowcs( dst, src, len, ps );
+}
+size_t wcrtomb_l( char *__restrict__ s, wchar_t wc, mbstate_t *__restrict__ ps,
+                  locale_t loc )
+{
+    __locale_raii __current( uselocale(loc), uselocale );
+    return wcrtomb( s, wc, ps );
+}
+size_t mbrtowc_l( wchar_t *__restrict__ pwc, const char *__restrict__ s,
+                  size_t n, mbstate_t *__restrict__ ps, locale_t loc )
+{
+    __locale_raii __current( uselocale(loc), uselocale );
+    return mbrtowc( pwc, s, n, ps );
+}
+size_t mbsnrtowcs_l( wchar_t *__restrict__ dst, const char **__restrict__ src,
+                     size_t nms, size_t len, mbstate_t *__restrict__ ps, locale_t loc )
+{
+    __locale_raii __current( uselocale(loc), uselocale );
+    return mbsnrtowcs( dst, src, nms, len, ps );
+}
+size_t wcsnrtombs_l( char *__restrict__ dst, const wchar_t **__restrict__ src,
+                     size_t nwc, size_t len, mbstate_t *__restrict__ ps, locale_t loc )
+{
+    __locale_raii __current( uselocale(loc), uselocale );
+    return wcsnrtombs( dst, src, nwc, len, ps );
+}
+wint_t btowc_l( int c, locale_t loc )
+{
+    __locale_raii __current( uselocale(loc), uselocale );
+    return btowc( c );
+}
+int wctob_l( wint_t c, locale_t loc )
+{
+    __locale_raii __current( uselocale(loc), uselocale );
+    return wctob( c );
+}
+
+int asprintf_l( char **ret, locale_t loc, const char *format, ... )
+{
+    va_list ap;
+    va_start( ap, format );
+    int result = vasprintf_l( ret, loc, format, ap );
+    va_end(ap);
+    return result;
+}
+int vasprintf_l( char **ret, locale_t loc, const char *format, va_list ap )
+{
+    __locale_raii __current( uselocale(loc), uselocale );
+    return vasprintf( ret, format, ap );
+}