diff --git a/ChangeLog b/ChangeLog
index 49892b61f5..341570161d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,8 @@
-Wed Oct 17 03:06:30 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Wed Oct 17 03:37:07 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* re.c (rb_reg_desc): set encoding.
+
+	* re.c (rb_reg_s_union): check encodings.
 
 	* enc/utf8.c (utf8_code_to_mbclen): 0xfe and 0xff are valid Unicode to
 	  be encoded to 2bytes in UTF-8.  [ruby-core:12700]
diff --git a/re.c b/re.c
index d6bff5ea94..605c40f176 100644
--- a/re.c
+++ b/re.c
@@ -266,6 +266,7 @@ rb_reg_desc(const char *s, long len, VALUE re)
 {
     VALUE str = rb_str_buf_new2("/");
 
+    rb_enc_copy(str, re);
     rb_reg_expr_str(str, s, len);
     rb_str_buf_cat2(str, "/");
     if (re) {
@@ -1798,7 +1799,7 @@ rb_reg_s_union(VALUE self, VALUE args0)
 		rb_enc_check(tmp, e);
 		v = rb_reg_s_quote(Qnil, e);
 	    }
-	    rb_str_buf_append(source, v);
+	    rb_str_append(source, v);
 	}
         return rb_class_new_instance(1, &source, rb_cRegexp);
     }