diff --git a/dlls/msvcr100/msvcr100.spec b/dlls/msvcr100/msvcr100.spec
index ab71711ec7d..108fae5f4e3 100644
--- a/dlls/msvcr100/msvcr100.spec
+++ b/dlls/msvcr100/msvcr100.spec
@@ -1518,7 +1518,7 @@
 @ cdecl _wcsupr_l(wstr ptr) MSVCRT__wcsupr_l
 @ cdecl _wcsupr_s(wstr long) MSVCRT__wcsupr_s
 @ cdecl _wcsupr_s_l(wstr long ptr) MSVCRT__wcsupr_s_l
-@ stub _wcsxfrm_l
+@ cdecl _wcsxfrm_l(ptr wstr long ptr) MSVCRT__wcsxfrm_l
 @ cdecl _wctime32(ptr) MSVCRT__wctime32
 @ stub _wctime32_s
 @ cdecl _wctime64(ptr) MSVCRT__wctime64
@@ -1877,7 +1877,7 @@
 @ cdecl wcstombs(ptr ptr long) MSVCRT_wcstombs
 @ cdecl wcstombs_s(ptr ptr long wstr long) MSVCRT_wcstombs_s
 @ cdecl wcstoul(wstr ptr long) MSVCRT_wcstoul
-@ stub wcsxfrm(ptr wstr long)
+@ cdecl wcsxfrm(ptr wstr long) MSVCRT_wcsxfrm
 @ cdecl wctob(long) MSVCRT_wctob
 @ cdecl wctomb(ptr long) MSVCRT_wctomb
 @ cdecl wctomb_s(ptr ptr long long) MSVCRT_wctomb_s
diff --git a/dlls/msvcr110/msvcr110.spec b/dlls/msvcr110/msvcr110.spec
index c231de98cf5..4f89b24ab0e 100644
--- a/dlls/msvcr110/msvcr110.spec
+++ b/dlls/msvcr110/msvcr110.spec
@@ -1877,7 +1877,7 @@
 @ cdecl _wcsupr_l(wstr ptr) MSVCRT__wcsupr_l
 @ cdecl _wcsupr_s(wstr long) MSVCRT__wcsupr_s
 @ cdecl _wcsupr_s_l(wstr long ptr) MSVCRT__wcsupr_s_l
-@ stub _wcsxfrm_l
+@ cdecl _wcsxfrm_l(ptr wstr long ptr) MSVCRT__wcsxfrm_l
 @ cdecl _wctime32(ptr) MSVCRT__wctime32
 @ stub _wctime32_s
 @ cdecl _wctime64(ptr) MSVCRT__wctime64
@@ -2236,7 +2236,7 @@
 @ cdecl wcstombs(ptr ptr long) MSVCRT_wcstombs
 @ cdecl wcstombs_s(ptr ptr long wstr long) MSVCRT_wcstombs_s
 @ cdecl wcstoul(wstr ptr long) MSVCRT_wcstoul
-@ stub wcsxfrm(ptr wstr long)
+@ cdecl wcsxfrm(ptr wstr long) MSVCRT_wcsxfrm
 @ cdecl wctob(long) MSVCRT_wctob
 @ cdecl wctomb(ptr long) MSVCRT_wctomb
 @ cdecl wctomb_s(ptr ptr long long) MSVCRT_wctomb_s
diff --git a/dlls/msvcr70/msvcr70.spec b/dlls/msvcr70/msvcr70.spec
index 016835955ac..1a94ee2cc09 100644
--- a/dlls/msvcr70/msvcr70.spec
+++ b/dlls/msvcr70/msvcr70.spec
@@ -870,7 +870,7 @@
 @ cdecl wcstol(wstr ptr long) ntdll.wcstol
 @ cdecl wcstombs(ptr ptr long) MSVCRT_wcstombs
 @ cdecl wcstoul(wstr ptr long) MSVCRT_wcstoul
-@ stub wcsxfrm(ptr wstr long)
+@ cdecl wcsxfrm(ptr wstr long) MSVCRT_wcsxfrm
 @ cdecl wctomb(ptr long) MSVCRT_wctomb
 @ varargs wprintf(wstr) MSVCRT_wprintf
 @ varargs wscanf(wstr) MSVCRT_wscanf
diff --git a/dlls/msvcr71/msvcr71.spec b/dlls/msvcr71/msvcr71.spec
index f5ff608b262..127a44071bf 100644
--- a/dlls/msvcr71/msvcr71.spec
+++ b/dlls/msvcr71/msvcr71.spec
@@ -866,7 +866,7 @@
 @ cdecl wcstol(wstr ptr long) ntdll.wcstol
 @ cdecl wcstombs(ptr ptr long) MSVCRT_wcstombs
 @ cdecl wcstoul(wstr ptr long) MSVCRT_wcstoul
-@ stub wcsxfrm(ptr wstr long)
+@ cdecl wcsxfrm(ptr wstr long) MSVCRT_wcsxfrm
 @ cdecl wctomb(ptr long) MSVCRT_wctomb
 @ varargs wprintf(wstr) MSVCRT_wprintf
 @ varargs wscanf(wstr) MSVCRT_wscanf
diff --git a/dlls/msvcr80/msvcr80.spec b/dlls/msvcr80/msvcr80.spec
index d4985bc5d63..302abe54237 100644
--- a/dlls/msvcr80/msvcr80.spec
+++ b/dlls/msvcr80/msvcr80.spec
@@ -1197,7 +1197,7 @@
 @ cdecl _wcsupr_l(wstr ptr) MSVCRT__wcsupr_l
 @ cdecl _wcsupr_s(wstr long) MSVCRT__wcsupr_s
 @ cdecl _wcsupr_s_l(wstr long ptr) MSVCRT__wcsupr_s_l
-@ stub _wcsxfrm_l
+@ cdecl _wcsxfrm_l(ptr wstr long ptr) MSVCRT__wcsxfrm_l
 @ cdecl _wctime32(ptr) MSVCRT__wctime32
 @ stub _wctime32_s
 @ cdecl _wctime64(ptr) MSVCRT__wctime64
@@ -1557,7 +1557,7 @@
 @ cdecl wcstombs(ptr ptr long) MSVCRT_wcstombs
 @ cdecl wcstombs_s(ptr ptr long wstr long) MSVCRT_wcstombs_s
 @ cdecl wcstoul(wstr ptr long) MSVCRT_wcstoul
-@ stub wcsxfrm(ptr wstr long)
+@ cdecl wcsxfrm(ptr wstr long) MSVCRT_wcsxfrm
 @ cdecl wctob(long) MSVCRT_wctob
 @ cdecl wctomb(ptr long) MSVCRT_wctomb
 @ cdecl wctomb_s(ptr ptr long long) MSVCRT_wctomb_s
diff --git a/dlls/msvcr90/msvcr90.spec b/dlls/msvcr90/msvcr90.spec
index c5ec79a030b..28d37d1447b 100644
--- a/dlls/msvcr90/msvcr90.spec
+++ b/dlls/msvcr90/msvcr90.spec
@@ -1173,7 +1173,7 @@
 @ cdecl _wcsupr_l(wstr ptr) MSVCRT__wcsupr_l
 @ cdecl _wcsupr_s(wstr long) MSVCRT__wcsupr_s
 @ cdecl _wcsupr_s_l(wstr long ptr) MSVCRT__wcsupr_s_l
-@ stub _wcsxfrm_l
+@ cdecl _wcsxfrm_l(ptr wstr long ptr) MSVCRT__wcsxfrm_l
 @ cdecl _wctime32(ptr) MSVCRT__wctime32
 @ stub _wctime32_s
 @ cdecl _wctime64(ptr) MSVCRT__wctime64
@@ -1530,7 +1530,7 @@
 @ cdecl wcstombs(ptr ptr long) MSVCRT_wcstombs
 @ cdecl wcstombs_s(ptr ptr long wstr long) MSVCRT_wcstombs_s
 @ cdecl wcstoul(wstr ptr long) MSVCRT_wcstoul
-@ stub wcsxfrm(ptr wstr long)
+@ cdecl wcsxfrm(ptr wstr long) MSVCRT_wcsxfrm
 @ cdecl wctob(long) MSVCRT_wctob
 @ cdecl wctomb(ptr long) MSVCRT_wctomb
 @ cdecl wctomb_s(ptr ptr long long) MSVCRT_wctomb_s
diff --git a/dlls/msvcrt/msvcrt.spec b/dlls/msvcrt/msvcrt.spec
index 82d352d1bbb..2349580246b 100644
--- a/dlls/msvcrt/msvcrt.spec
+++ b/dlls/msvcrt/msvcrt.spec
@@ -1134,7 +1134,7 @@
 @ cdecl _wcsupr_l(wstr ptr) MSVCRT__wcsupr_l
 @ cdecl _wcsupr_s(wstr long) MSVCRT__wcsupr_s
 @ cdecl _wcsupr_s_l(wstr long ptr) MSVCRT__wcsupr_s_l
-# stub _wcsxfrm_l(ptr wstr long ptr)
+@ cdecl _wcsxfrm_l(ptr wstr long ptr) MSVCRT__wcsxfrm_l
 @ cdecl _wctime(ptr) MSVCRT__wctime
 @ cdecl _wctime32(ptr) MSVCRT__wctime32
 # stub _wctime32_s(ptr long ptr)
@@ -1509,7 +1509,7 @@
 @ cdecl wcstombs(ptr ptr long) MSVCRT_wcstombs
 @ cdecl wcstombs_s(ptr ptr long wstr long) MSVCRT_wcstombs_s
 @ cdecl wcstoul(wstr ptr long) MSVCRT_wcstoul
-@ stub wcsxfrm(ptr wstr long)
+@ cdecl wcsxfrm(ptr wstr long) MSVCRT_wcsxfrm
 @ cdecl wctob(long) MSVCRT_wctob
 @ cdecl wctomb(ptr long) MSVCRT_wctomb
 @ cdecl wctomb_s(ptr ptr long long) MSVCRT_wctomb_s
diff --git a/dlls/msvcrt/wcs.c b/dlls/msvcrt/wcs.c
index 7c299a7d8bb..c2b8f587398 100644
--- a/dlls/msvcrt/wcs.c
+++ b/dlls/msvcrt/wcs.c
@@ -2056,3 +2056,61 @@ int CDECL MSVCRT_wcsncmp(const MSVCRT_wchar_t *str1, const MSVCRT_wchar_t *str2,
 {
     return strncmpW(str1, str2, n);
 }
+
+/*********************************************************************
+ *              _wcsxfrm_l (MSVCRT.@)
+ */
+MSVCRT_size_t CDECL MSVCRT__wcsxfrm_l(MSVCRT_wchar_t *dest, const MSVCRT_wchar_t *src,
+        MSVCRT_size_t len, MSVCRT__locale_t locale)
+{
+    MSVCRT_pthreadlocinfo locinfo;
+    int i, ret;
+
+    if(!MSVCRT_CHECK_PMT(src)) return INT_MAX;
+    if(!MSVCRT_CHECK_PMT(dest || !len)) return INT_MAX;
+
+    if(len > INT_MAX) {
+        FIXME("len > INT_MAX not supported\n");
+        len = INT_MAX;
+    }
+
+    if(!locale)
+        locinfo = get_locinfo();
+    else
+        locinfo = locale->locinfo;
+
+    if(!locinfo->lc_handle[MSVCRT_LC_COLLATE]) {
+        MSVCRT_wcsncpy(dest, src, len);
+        return strlenW(src);
+    }
+
+    ret = LCMapStringW(locinfo->lc_handle[MSVCRT_LC_COLLATE],
+            LCMAP_SORTKEY, src, -1, NULL, 0);
+    if(!ret) {
+        if(len) dest[0] = 0;
+        *MSVCRT__errno() = MSVCRT_EILSEQ;
+        return INT_MAX;
+    }
+    if(!len) return ret-1;
+
+    if(ret > len) {
+        dest[0] = 0;
+        *MSVCRT__errno() = MSVCRT_ERANGE;
+        return ret-1;
+    }
+
+    ret = LCMapStringW(locinfo->lc_handle[MSVCRT_LC_COLLATE],
+            LCMAP_SORTKEY, src, -1, dest, len) - 1;
+    for(i=ret; i>=0; i--)
+        dest[i] = ((unsigned char*)dest)[i];
+    return ret;
+}
+
+/*********************************************************************
+ *              wcsxfrm (MSVCRT.@)
+ */
+MSVCRT_size_t CDECL MSVCRT_wcsxfrm(MSVCRT_wchar_t *dest,
+        const MSVCRT_wchar_t *src, MSVCRT_size_t len)
+{
+    return MSVCRT__wcsxfrm_l(dest, src, len, NULL);
+}