diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index d85bb0aa4..3c5d3e537 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,7 @@
+2009-04-18  Corinna Vinschen  <corinna@vinschen.de>
+
+	* dcrt0.cc (globify): Only call mbtowc for non-ascii chars.
+
 2009-04-17  Corinna Vinschen  <corinna@vinschen.de>
 
 	* dcrt0.cc (globify): Make multibyte-aware.
diff --git a/winsup/cygwin/dcrt0.cc b/winsup/cygwin/dcrt0.cc
index eddd11479..90960afd0 100644
--- a/winsup/cygwin/dcrt0.cc
+++ b/winsup/cygwin/dcrt0.cc
@@ -229,7 +229,7 @@ globify (char *word, char **&argv, int &argc, int &argvlen)
 	    else if (s[1] == quote || s[1] == '\\')
 	      s++;
 	    *p++ = '\\';
-	    size_t cnt = mbtowc (NULL, s, MB_CUR_MAX);
+	    size_t cnt = isascii (*s) ? 1 : mbtowc (NULL, s, MB_CUR_MAX);
 	    if (cnt <= 1 || cnt == (size_t)-1)
 	      *p++ = *s;
 	    else