diff --git a/ChangeLog b/ChangeLog
index f7144b218b..2606aa3875 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jan 24 16:53:06 2008  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* re.c (rb_reg_initialize): 7bit clean regexp should be US-ASCII.
+	  [ruby-dev:33346]
+
 Thu Jan 24 16:31:04 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* io.c (rb_io_getline_fast): the end point of left_char_head()
diff --git a/re.c b/re.c
index 46d0bbfcb7..562c151c7c 100644
--- a/re.c
+++ b/re.c
@@ -2008,7 +2008,7 @@ rb_reg_initialize(VALUE obj, const char *s, int len, rb_encoding *enc,
 	}
     }
     else if (!(options & ARG_ENCODING_FIXED)) {
-        enc = a_enc;
+       enc = rb_usascii_encoding();
     }
 
     rb_enc_associate((VALUE)re, enc);