diff --git a/dlls/msvcrt/mbcs.c b/dlls/msvcrt/mbcs.c
index 166af32cd27..fa25a7092e3 100644
--- a/dlls/msvcrt/mbcs.c
+++ b/dlls/msvcrt/mbcs.c
@@ -220,7 +220,7 @@ threadmbcinfo* create_mbcinfo(int cp, LCID lcid, threadmbcinfo *old_mbcinfo)
   WORD chartypes[256];
   char bufA[256];
   WCHAR bufW[256], lowW[256], upW[256];
-  int charcount;
+  int charcount, maxchar;
   int ret;
   int i;
 
@@ -288,7 +288,7 @@ threadmbcinfo* create_mbcinfo(int cp, LCID lcid, threadmbcinfo *old_mbcinfo)
     bytes += 2;
   }
 
-  if (cpi.MaxCharSize > 1)
+  if (cpi.MaxCharSize == 2)
   {
     /* trail bytes not available through kernel32 but stored in a structure in msvcrt */
     struct cp_extra_info_t *cpextra = g_cpextrainfo;
@@ -316,10 +316,12 @@ threadmbcinfo* create_mbcinfo(int cp, LCID lcid, threadmbcinfo *old_mbcinfo)
   else
     mbcinfo->ismbcodepage = 0;
 
+  maxchar = (newcp == CP_UTF8) ? 128 : 256;
+
   /* we can't use GetStringTypeA directly because we don't have a locale - only a code page
    */
   charcount = 0;
-  for (i = 0; i < 256; i++)
+  for (i = 0; i < maxchar; i++)
     if (!(mbcinfo->mbctype[i + 1] & _M1))
       bufA[charcount++] = i;
 
@@ -335,7 +337,7 @@ threadmbcinfo* create_mbcinfo(int cp, LCID lcid, threadmbcinfo *old_mbcinfo)
   LCMapStringW(lcid, LCMAP_UPPERCASE, bufW, charcount, upW, charcount);
 
   charcount = 0;
-  for (i = 0; i < 256; i++)
+  for (i = 0; i < maxchar; i++)
     if (!(mbcinfo->mbctype[i + 1] & _M1))
     {
       if (chartypes[charcount] & C1_UPPER)
@@ -359,7 +361,7 @@ threadmbcinfo* create_mbcinfo(int cp, LCID lcid, threadmbcinfo *old_mbcinfo)
   }
 
   charcount = 0;
-  for (i = 0; i < 256; i++)
+  for (i = 0; i < maxchar; i++)
   {
     if(!(mbcinfo->mbctype[i + 1] & _M1))
     {