diff --git a/ChangeLog b/ChangeLog
index 05e115af8b..c6933f2315 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Fri Aug 22 11:36:31 2008  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* dir.c (dir_enc_str_new): set US-ASCII to the path
+	  when the path is 7bit string and encoding is ASCII compatible.
+
+	* dir.c (push_glob): set file system encoding when argument encoding
+	  is US-ASCII.
+
 Fri Aug 22 11:30:38 2008  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* dir.c (dir_enc_str_new): renamed from dir_enc_str.
diff --git a/dir.c b/dir.c
index 34c4024fd8..9e55165a2f 100644
--- a/dir.c
+++ b/dir.c
@@ -427,6 +427,9 @@ static VALUE
 dir_enc_str_new(const char *p, long len, rb_encoding *enc)
 {
     VALUE path = rb_tainted_str_new(p, len);
+    if (rb_enc_asciicompat(enc) && rb_enc_str_asciionly_p(path)) {
+	enc = rb_usascii_encoding();
+    }
     rb_enc_associate(path, enc);
     return path;
 }
@@ -1533,6 +1536,7 @@ push_glob(VALUE ary, VALUE str, int flags)
     struct glob_args args;
     rb_encoding *enc = rb_enc_get(str);
 
+    if (enc == rb_usascii_encoding()) enc = rb_filesystem_encoding();
     args.func = push_pattern;
     args.value = ary;
     args.enc = enc;