diff --git a/ChangeLog b/ChangeLog
index c400fdb1d2..1c767078bc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Wed Dec 29 18:23:46 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* re.c (rb_reg_expr_str): need to escape if the coderage is invalid.
+
 Wed Dec 29 10:06:51 2010  Tanaka Akira  <akr@fsij.org>
 
 	* signal.c: parenthesize macro arguments.
@@ -12,8 +16,6 @@ Wed Dec 29 07:07:06 2010  Eric Hodel  <drbrain@segment7.net>
 
 Tue Dec 28 18:36:38 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
 
-	* re.c (rb_reg_expr_str): need to escape if the coderage is invalid.
-
 	* error.c, include/ruby/intern.h (rb_compile_error_with_enc): new
 	  function to raise syntax error, with source encoding'ed message.
 
diff --git a/re.c b/re.c
index 047acb62f9..2157ee8764 100644
--- a/re.c
+++ b/re.c
@@ -321,11 +321,14 @@ rb_reg_expr_str(VALUE str, const char *s, long len,
 	rb_encoding *enc, rb_encoding *resenc)
 {
     const char *p, *pend;
+    int cr = ENC_CODERANGE_UNKNOWN;
     int need_escape = 0;
     int c, clen;
 
     p = s; pend = p + len;
-    if (rb_enc_asciicompat(enc)) {
+    rb_str_coderange_scan_restartable(p, pend, enc, &cr);
+    if (rb_enc_asciicompat(enc) &&
+	(cr == ENC_CODERANGE_VALID || cr == ENC_CODERANGE_7BIT)) {
 	while (p < pend) {
 	    c = rb_enc_ascget(p, pend, &clen, enc);
 	    if (c == -1) {