diff --git complete.c complete.c
index e67cfeb..30add90 100644
--- complete.c
+++ complete.c
@@ -2085,39 +2085,85 @@ complete_fncmp (convfn, convlen, filename, filename_len)
      int filename_len;
 {
   register char *s1, *s2;
+  char c1, c2;
   int d, len;
-
-  /* Otherwise, if these match up to the length of filename, then
-     it is a match. */
+#if defined (HANDLE_MULTIBYTE)
+  wchar_t wc1, wc2; 
+  mbstate_t ps1, ps2;
+  int v;
+#endif
+/* Case-insensitive comparison treating _ and - as equivalent */
   if (_rl_completion_case_fold && _rl_completion_case_map)
     {
-      /* Case-insensitive comparison treating _ and - as equivalent */
-      if (filename_len == 0)
-	return 1;
       if (convlen < filename_len)
 	return 0;
-      s1 = (char *)convfn;
-      s2 = (char *)filename;
-      len = filename_len;
-      do
+      s1 = (char*)convfn;
+      s2 = (char*)filename;
+#if defined (HANDLE_MULTIBYTE)
+      if (MB_CUR_MAX == 1 || rl_byte_oriented != 0)
+	goto case_map_byte;
+
+      memset (&ps1, 0, sizeof (mbstate_t));
+      memset (&ps2, 0, sizeof (mbstate_t));
+
+      /* convlen and filename_len in every interation is ok here */
+      /* as we believe multibyte sequences are ok */
+      while ((v = mbrtowc (&wc1, s1, convlen, &ps1), wc1) &&
+		  (mbrtowc (&wc2, s2, filename_len, &ps2), wc2)) 
+	{
+	  s1 += v;
+	  s2 += v;
+	  if ((wc1 == '-' || wc1 == '_') &&
+	      (wc2 == '-' || wc2 == '_'))
+	    continue;
+	  if (towlower(wc1) != towlower(wc2)) 
+	    return 0;
+	}
+      return 1;
+#endif
+case_map_byte:
+	while ((c1 = *s1++) && (c2 = *s2++))
 	{
-	  d = _rl_to_lower (*s1) - _rl_to_lower (*s2);
-	  /* *s1 == [-_] && *s2 == [-_] */
-	  if ((*s1 == '-' || *s1 == '_') && (*s2 == '-' || *s2 == '_'))
-	    d = 0;
-	  if (d != 0)
+	  if ((c1 == '-' || c1 == '_') &&
+	      (c2 == '-' || c2 == '_'))
+	    continue;
+	  if (_rl_to_lower(c1) != _rl_to_lower(c2))
 	    return 0;
-	  s1++; s2++;	/* already checked convlen >= filename_len */
 	}
-      while (--len != 0);
       return 1;
     }
   else if (_rl_completion_case_fold)
     {
-      if ((_rl_to_lower (convfn[0]) == _rl_to_lower (filename[0])) &&
-	  (convlen >= filename_len) &&
-	  (_rl_strnicmp (filename, convfn, filename_len) == 0))
-	return 1;
+      if (convlen < filename_len)
+	return 0;
+      s1 = (char*)convfn;
+      s2 = (char*)filename;
+#if defined (HANDLE_MULTIBYTE)
+      if (MB_CUR_MAX == 1 || rl_byte_oriented != 0)
+	goto case_byte;
+
+      memset (&ps1, 0, sizeof (mbstate_t));
+      memset (&ps2, 0, sizeof (mbstate_t));
+
+      /* convlen and filename_len in every interation is ok here */
+      /* as we believe multibyte sequences are ok */
+      while ((v = mbrtowc (&wc1, s1, convlen, &ps1), wc1) &&
+		  (mbrtowc (&wc2, s2, filename_len, &ps2), wc2)) 
+	{
+	  if (towlower(wc1) != towlower(wc2)) 
+	    return 0;
+	  s1 += v;
+	  s2 += v;
+	}
+      return 1;
+#endif
+case_byte:
+      while ((c1 = *s1++) && (c2 = *s2++))
+	{
+	  if (_rl_to_lower(c1) != _rl_to_lower(c2))
+	    return 0;
+	}
+      return 1;
     }
   else
     {