--- a/include/wine/test.h
+++ b/include/wine/test.h
@@ -28,6 +28,13 @@
 #include <winbase.h>
 #include <wine/debug.h>
 
+#ifdef __WINE_CONFIG_H
+#error config.h should not be used in Wine tests
+#endif
+#ifdef __WINE_WINE_UNICODE_H
+#error wine/unicode.h should not be used in Wine tests
+#endif
+
 #ifndef INVALID_FILE_ATTRIBUTES
 #define INVALID_FILE_ATTRIBUTES  (~0u)
 #endif
--- /dev/null
+++ b/include/wine/unicode.h
@@ -0,0 +1,178 @@
+/*
+ * Wine internal Unicode definitions
+ *
+ * Copyright 2000 Alexandre Julliard
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#if 0
+#pragma makedep install
+#endif
+
+#ifndef __WINE_WINE_UNICODE_H
+#define __WINE_WINE_UNICODE_H
+
+#include <stdarg.h>
+
+#include <windef.h>
+#include <winbase.h>
+#include <winnls.h>
+#include <winternl.h>
+
+#ifdef __WINE_USE_MSVCRT
+#error This file should not be used with msvcrt headers
+#endif
+
+#ifndef WINE_UNICODE_INLINE
+#define WINE_UNICODE_INLINE static FORCEINLINE
+#endif
+
+WINE_UNICODE_INLINE WCHAR tolowerW( WCHAR ch )
+{
+    return RtlDowncaseUnicodeChar( ch );
+}
+
+WINE_UNICODE_INLINE WCHAR toupperW( WCHAR ch )
+{
+    return RtlUpcaseUnicodeChar( ch );
+}
+
+WINE_UNICODE_INLINE int isspaceW( WCHAR wc )
+{
+    unsigned short type;
+    GetStringTypeW( CT_CTYPE1, &wc, 1, &type );
+    return type & C1_SPACE;
+}
+
+WINE_UNICODE_INLINE unsigned int strlenW( const WCHAR *str )
+{
+    const WCHAR *s = str;
+    while (*s) s++;
+    return s - str;
+}
+
+WINE_UNICODE_INLINE WCHAR *strcpyW( WCHAR *dst, const WCHAR *src )
+{
+    WCHAR *p = dst;
+    while ((*p++ = *src++));
+    return dst;
+}
+
+WINE_UNICODE_INLINE WCHAR *strcatW( WCHAR *dst, const WCHAR *src )
+{
+    strcpyW( dst + strlenW(dst), src );
+    return dst;
+}
+
+WINE_UNICODE_INLINE WCHAR *strrchrW( const WCHAR *str, WCHAR ch )
+{
+    WCHAR *ret = NULL;
+    do { if (*str == ch) ret = (WCHAR *)(ULONG_PTR)str; } while (*str++);
+    return ret;
+}
+
+WINE_UNICODE_INLINE int strcmpiW( const WCHAR *str1, const WCHAR *str2 )
+{
+    for (;;)
+    {
+        int ret = tolowerW(*str1) - tolowerW(*str2);
+        if (ret || !*str1) return ret;
+        str1++;
+        str2++;
+    }
+}
+
+WINE_UNICODE_INLINE int strncmpiW( const WCHAR *str1, const WCHAR *str2, int n )
+{
+    int ret = 0;
+    for ( ; n > 0; n--, str1++, str2++)
+        if ((ret = tolowerW(*str1) - tolowerW(*str2)) || !*str1) break;
+    return ret;
+}
+
+WINE_UNICODE_INLINE LONG strtolW( LPCWSTR s, LPWSTR *end, INT base )
+{
+    BOOL negative = FALSE, empty = TRUE;
+    LONG ret = 0;
+
+    if (base < 0 || base == 1 || base > 36) return 0;
+    if (end) *end = (WCHAR *)s;
+    while (isspaceW(*s)) s++;
+
+    if (*s == '-')
+    {
+        negative = TRUE;
+        s++;
+    }
+    else if (*s == '+') s++;
+
+    if ((base == 0 || base == 16) && s[0] == '0' && (s[1] == 'x' || s[1] == 'X'))
+    {
+        base = 16;
+        s += 2;
+    }
+    if (base == 0) base = s[0] != '0' ? 10 : 8;
+
+    while (*s)
+    {
+        int v;
+
+        if ('0' <= *s && *s <= '9') v = *s - '0';
+        else if ('A' <= *s && *s <= 'Z') v = *s - 'A' + 10;
+        else if ('a' <= *s && *s <= 'z') v = *s - 'a' + 10;
+        else break;
+        if (v >= base) break;
+        if (negative) v = -v;
+        s++;
+        empty = FALSE;
+
+        if (!negative && (ret > MAXLONG / base || ret * base > MAXLONG - v))
+            ret = MAXLONG;
+        else if (negative && (ret < (LONG)MINLONG / base || ret * base < (LONG)(MINLONG - v)))
+            ret = MINLONG;
+        else
+            ret = ret * base + v;
+    }
+
+    if (end && !empty) *end = (WCHAR *)s;
+    return ret;
+}
+
+NTSYSAPI int __cdecl _vsnwprintf(WCHAR*,size_t,const WCHAR*,__ms_va_list);
+
+static inline int WINAPIV snprintfW( WCHAR *str, size_t len, const WCHAR *format, ...)
+{
+    int retval;
+    __ms_va_list valist;
+    __ms_va_start(valist, format);
+    retval = _vsnwprintf(str, len, format, valist);
+    __ms_va_end(valist);
+    return retval;
+}
+
+static inline int WINAPIV sprintfW( WCHAR *str, const WCHAR *format, ...)
+{
+    int retval;
+    __ms_va_list valist;
+    __ms_va_start(valist, format);
+    retval = _vsnwprintf(str, MAXLONG, format, valist);
+    __ms_va_end(valist);
+    return retval;
+}
+
+#undef WINE_UNICODE_INLINE
+
+#endif  /* __WINE_WINE_UNICODE_H */
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -873,6 +873,7 @@
 	wine/strmbase.h \
 	wine/svcctl.idl \
 	wine/test.h \
+	wine/unicode.h \
 	wine/unixlib.h \
 	wine/vulkan.h \
 	wine/vulkan_driver.h \