diff --git a/dlls/msvcr100/msvcr100.spec b/dlls/msvcr100/msvcr100.spec
index 9012225b040..ef6d3544497 100644
--- a/dlls/msvcr100/msvcr100.spec
+++ b/dlls/msvcr100/msvcr100.spec
@@ -1557,7 +1557,7 @@
 @ cdecl _wmakepath_s(ptr long wstr wstr wstr wstr) msvcrt._wmakepath_s
 @ cdecl _wmkdir(wstr) msvcrt._wmkdir
 @ cdecl _wmktemp(wstr) msvcrt._wmktemp
-@ stub _wmktemp_s
+@ cdecl _wmktemp_s(wstr long) msvcrt._wmktemp_s
 @ varargs _wopen(wstr long) msvcrt._wopen
 @ cdecl _wperror(wstr) msvcrt._wperror
 @ extern _wpgmptr msvcrt._wpgmptr
diff --git a/dlls/msvcr110/msvcr110.spec b/dlls/msvcr110/msvcr110.spec
index ad6d15929ee..dd768788037 100644
--- a/dlls/msvcr110/msvcr110.spec
+++ b/dlls/msvcr110/msvcr110.spec
@@ -1919,7 +1919,7 @@
 @ cdecl _wmakepath_s(ptr long wstr wstr wstr wstr) msvcrt._wmakepath_s
 @ cdecl _wmkdir(wstr) msvcrt._wmkdir
 @ cdecl _wmktemp(wstr) msvcrt._wmktemp
-@ stub _wmktemp_s
+@ cdecl _wmktemp_s(wstr long) msvcrt._wmktemp_s
 @ varargs _wopen(wstr long) msvcrt._wopen
 @ cdecl _wperror(wstr) msvcrt._wperror
 @ extern _wpgmptr msvcrt._wpgmptr
diff --git a/dlls/msvcr80/msvcr80.spec b/dlls/msvcr80/msvcr80.spec
index 59ee88d0df3..87fbc5da3a5 100644
--- a/dlls/msvcr80/msvcr80.spec
+++ b/dlls/msvcr80/msvcr80.spec
@@ -1238,7 +1238,7 @@
 @ cdecl _wmakepath_s(ptr long wstr wstr wstr wstr) msvcrt._wmakepath_s
 @ cdecl _wmkdir(wstr) msvcrt._wmkdir
 @ cdecl _wmktemp(wstr) msvcrt._wmktemp
-@ stub _wmktemp_s
+@ cdecl _wmktemp_s(wstr long) msvcrt._wmktemp_s
 @ varargs _wopen(wstr long) msvcrt._wopen
 @ cdecl _wperror(wstr) msvcrt._wperror
 @ extern _wpgmptr msvcrt._wpgmptr
diff --git a/dlls/msvcr90/msvcr90.spec b/dlls/msvcr90/msvcr90.spec
index 5d2ebf6d120..98000231c57 100644
--- a/dlls/msvcr90/msvcr90.spec
+++ b/dlls/msvcr90/msvcr90.spec
@@ -1211,7 +1211,7 @@
 @ cdecl _wmakepath_s(ptr long wstr wstr wstr wstr) msvcrt._wmakepath_s
 @ cdecl _wmkdir(wstr) msvcrt._wmkdir
 @ cdecl _wmktemp(wstr) msvcrt._wmktemp
-@ stub _wmktemp_s
+@ cdecl _wmktemp_s(wstr long) msvcrt._wmktemp_s
 @ varargs _wopen(wstr long) msvcrt._wopen
 @ cdecl _wperror(wstr) msvcrt._wperror
 @ extern _wpgmptr msvcrt._wpgmptr
diff --git a/dlls/msvcrt/file.c b/dlls/msvcrt/file.c
index 35e2c004b83..8403b4b9517 100644
--- a/dlls/msvcrt/file.c
+++ b/dlls/msvcrt/file.c
@@ -1756,6 +1756,45 @@ char * CDECL MSVCRT__mktemp(char *pattern)
   return NULL;
 }
 
+/*********************************************************************
+ *		_wmktemp_s (MSVCRT.@)
+ */
+int CDECL MSVCRT__wmktemp_s(MSVCRT_wchar_t *pattern, MSVCRT_size_t size)
+{
+    DWORD len, xno, id;
+
+    if(!MSVCRT_CHECK_PMT(pattern!=NULL))
+        return MSVCRT_EINVAL;
+
+    for(len=0; len<size; len++)
+        if(!pattern[len])
+            break;
+    if(!MSVCRT_CHECK_PMT(len!=size && len>=6)) {
+        if(size)
+            pattern[0] = 0;
+        return MSVCRT_EINVAL;
+    }
+
+    for(xno=1; xno<=6; xno++)
+        if(!MSVCRT_CHECK_PMT(pattern[len-xno] == 'X'))
+            return MSVCRT_EINVAL;
+
+    id = GetCurrentProcessId();
+    for(xno=1; xno<6; xno++) {
+        pattern[len-xno] = id%10 + '0';
+        id /= 10;
+    }
+
+    for(pattern[len-6]='a'; pattern[len-6]<='z'; pattern[len-6]++) {
+        if(GetFileAttributesW(pattern) == INVALID_FILE_ATTRIBUTES)
+            return 0;
+    }
+
+    pattern[0] = 0;
+    *MSVCRT__errno() = MSVCRT_EEXIST;
+    return MSVCRT_EEXIST;
+}
+
 /*********************************************************************
  *		_wmktemp (MSVCRT.@)
  */
diff --git a/dlls/msvcrt/msvcrt.spec b/dlls/msvcrt/msvcrt.spec
index e566440e320..e0e628710d1 100644
--- a/dlls/msvcrt/msvcrt.spec
+++ b/dlls/msvcrt/msvcrt.spec
@@ -1180,7 +1180,7 @@
 @ cdecl _wmakepath_s(ptr long wstr wstr wstr wstr)
 @ cdecl _wmkdir(wstr) MSVCRT__wmkdir
 @ cdecl _wmktemp(wstr) MSVCRT__wmktemp
-# stub _wmktemp_s(wstr long)
+@ cdecl _wmktemp_s(wstr long) MSVCRT__wmktemp_s
 @ varargs _wopen(wstr long) MSVCRT__wopen
 # stub _woutput_s
 @ stub _wperror(wstr)