diff --git "a/sdk/lib/crt/mbstring/ismbc.c" "b/sdk/lib/crt/mbstring/ismbc.c"
index 087700e3592..e228b736ad8 100644
--- "a/sdk/lib/crt/mbstring/ismbc.c"
+++ "b/sdk/lib/crt/mbstring/ismbc.c"
@@ -14,6 +14,82 @@
 #include <mbstring.h>
 #include <mbctype.h>
 
+#if _MSVCR_VER <= 110
+# define B110 _BLANK
+#else
+# define B110 0
+#endif
+#if _MSVCR_VER == 120
+# define D120 0
+#else
+# define D120 4
+#endif
+
+#if _MSVCR_VER >= 140
+# define S140 _SPACE
+# define L140 _LOWER | 0x100
+# define C140 _CONTROL
+#else
+# define S140 0
+# define L140 0
+# define C140 0
+#endif
+
+WORD MSVCRT__wctype[257] =
+{
+    0,
+    /* 00 */
+    0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020,
+    0x0020, 0x0028 | B110, 0x0028, 0x0028, 0x0028, 0x0028, 0x0020, 0x0020,
+    /* 10 */
+    0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020,
+    0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020,
+    /* 20 */
+    0x0048, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
+    0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
+    /* 30 */
+    0x0084, 0x0084, 0x0084, 0x0084, 0x0084, 0x0084, 0x0084, 0x0084,
+    0x0084, 0x0084, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
+    /* 40 */
+    0x0010, 0x0181, 0x0181, 0x0181, 0x0181, 0x0181, 0x0181, 0x0101,
+    0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101,
+    /* 50 */
+    0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101,
+    0x0101, 0x0101, 0x0101, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
+    /* 60 */
+    0x0010, 0x0182, 0x0182, 0x0182, 0x0182, 0x0182, 0x0182, 0x0102,
+    0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102,
+    /* 70 */
+    0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102,
+    0x0102, 0x0102, 0x0102, 0x0010, 0x0010, 0x0010, 0x0010, 0x0020,
+    /* 80 */
+    0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020 | S140, 0x0020, 0x0020,
+    0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020,
+    /* 90 */
+    0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020,
+    0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020, 0x0020,
+    /* a0 */
+    0x0008 | B110, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
+    0x0010, 0x0010, 0x0010 | L140, 0x0010, 0x0010, 0x0010 | C140, 0x0010, 0x0010,
+    /* b0 */
+    0x0010, 0x0010, 0x0010 | D120, 0x0010 | D120, 0x0010, 0x0010 | L140, 0x0010, 0x0010,
+    0x0010, 0x0010 | D120, 0x0010 | L140, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
+    /* c0 */
+    0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101,
+    0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101,
+    /* d0 */
+    0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0010,
+    0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0101, 0x0102,
+    /* e0 */
+    0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102,
+    0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102,
+    /* f0 */
+    0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0010,
+    0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102, 0x0102
+};
+
+WORD *MSVCRT__pwctype = MSVCRT__wctype + 1;
+
 /*
  * @implemented
  */
@@ -61,12 +137,70 @@ int _ismbcsymbol( unsigned int c )
 	return (c >= 0x8141 && c <= 0x817e) || (c >= 0x8180 && c <= 0x81ac);
 }
 
+static wchar_t MSVCRT_mbc_to_wc_l(unsigned int ch, _locale_t locale)
+{
+    MSVCRT_pthreadmbcinfo mbcinfo = get_mbcinfo(); // ReactOS modified
+
+    wchar_t chW;
+    char mbch[2];
+    int n_chars;
+
+    if (ch <= 0xff) {
+        mbch[0] = ch;
+        n_chars = 1;
+    } else {
+        mbch[0] = (ch >> 8) & 0xff;
+        mbch[1] = ch & 0xff;
+        n_chars = 2;
+    }
+    if (!MultiByteToWideChar(mbcinfo->mbcodepage, 0, mbch, n_chars, &chW, 1))
+    {
+        WARN("MultiByteToWideChar failed on %x\n", ch);
+        return 0;
+    }
+    return chW;
+}
+
+/*********************************************************************
+ *		_iswctype_l (MSVCRT.@)
+ */
+INT CDECL MSVCRT_iswctype_l( wchar_t wc, wctype_t type, _locale_t locale )
+{
+    WORD ct;
+
+    if (wc == WEOF) return 0;
+    if (wc < 256) return MSVCRT__pwctype[wc] & type;
+
+    if (!GetStringTypeW(CT_CTYPE1, &wc, 1, &ct))
+    {
+        ERR("GetStringTypeW failed for %x\n", wc);
+        return 0;
+    }
+    return ct & type;
+}
+
+/*********************************************************************
+ *		_iswspace_l (MSVCRT.@)
+ */
+INT CDECL MSVCRT_iswspace_l( wchar_t wc, _locale_t locale )
+{
+    return MSVCRT_iswctype_l( wc, _SPACE, locale );
+}
+
+/*********************************************************************
+ *              _ismbcspace_l (MSVCRT.@)
+ */
+int CDECL MSVCRT_ismbcspace_l(unsigned int ch, _locale_t locale)
+{
+    return MSVCRT_iswspace_l( MSVCRT_mbc_to_wc_l(ch, locale), locale );
+}
+
 /*
  * @implemented
  */
 int _ismbcspace( unsigned int c )
 {
-	return ((c) == 0x8140);
+    return MSVCRT_ismbcspace_l( c, NULL );
 }
 /*
  * @implemented