diff --git a/reactos/lib/3rdparty/libwine/CMakeLists.txt b/reactos/lib/3rdparty/libwine/CMakeLists.txt
index 8f4c440fcd6..d8059eb51b1 100644
--- a/reactos/lib/3rdparty/libwine/CMakeLists.txt
+++ b/reactos/lib/3rdparty/libwine/CMakeLists.txt
@@ -8,7 +8,7 @@ list(APPEND SOURCE
     isinf.c
     isnan.c
     loader.c
-    wctype.c
+    ../../sdk/crt/string/wctype.c
     register.c
 #    string.c implements _stricmp, already shipped with crt
 )
diff --git a/reactos/lib/sdk/crt/crt.cmake b/reactos/lib/sdk/crt/crt.cmake
index 6abd6fe87d2..f5f4b8e2e2c 100644
--- a/reactos/lib/sdk/crt/crt.cmake
+++ b/reactos/lib/sdk/crt/crt.cmake
@@ -281,6 +281,7 @@ list(APPEND CRT_SOURCE
     string/wcs.c
     string/wcstol.c
     string/wcstoul.c
+    string/wctype.c
     string/wsplitp.c
     string/wtoi.c
     string/wtoi64.c
diff --git a/reactos/lib/sdk/crt/string/ctype.c b/reactos/lib/sdk/crt/string/ctype.c
index 28dcda5ab66..7c5188570f9 100644
--- a/reactos/lib/sdk/crt/string/ctype.c
+++ b/reactos/lib/sdk/crt/string/ctype.c
@@ -551,6 +551,8 @@ const unsigned short _wctype[] = {
 const unsigned short *_pctype = _ctype + 1;
 const unsigned short *_pwctype = _wctype + 1;
 
+extern const unsigned short wine_wctype_table[];
+
 /*
  * @implemented
  */
@@ -587,7 +589,7 @@ int _isctype (int c, int ctypeFlags)
  */
 int iswctype(wint_t wc, wctype_t wctypeFlags)
 {
-   return (_pwctype[(unsigned char)(wc & 0xFF)] & wctypeFlags);
+   return (wine_wctype_table[wine_wctype_table[wc >> 8] + (wc & 0xff)] & wctypeFlags);
 }
 
 /*
@@ -597,7 +599,7 @@ int iswctype(wint_t wc, wctype_t wctypeFlags)
  */
 int is_wctype(wint_t wc, wctype_t wctypeFlags)
 {
-   return (_pwctype[(unsigned char)(wc & 0xFF)] & wctypeFlags);
+   return (wine_wctype_table[wine_wctype_table[wc >> 8] + (wc & 0xff)] & wctypeFlags);
 }
 
 /*
diff --git a/reactos/lib/3rdparty/libwine/wctype.c b/reactos/lib/sdk/crt/string/wctype.c
similarity index 100%
rename from reactos/lib/3rdparty/libwine/wctype.c
rename to reactos/lib/sdk/crt/string/wctype.c