diff --git a/ChangeLog b/ChangeLog
index ed9511f49d..1e7202af8c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Feb  1 11:44:22 2008  Tanaka Akira  <akr@fsij.org>
+
+	* tool/compile_prelude.rb (C_ESC): use octal escape to avoid
+	  "\x09for (;;) ..." to be interpret the first character 0x9f.
+
 Thu Jan 31 23:06:42 2008  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* test/ruby/test_bignum.rb: suppress warnings during test.
diff --git a/tool/compile_prelude.rb b/tool/compile_prelude.rb
index 2ffccc0d93..04ecdf4444 100644
--- a/tool/compile_prelude.rb
+++ b/tool/compile_prelude.rb
@@ -16,8 +16,8 @@ C_ESC = {
   "\n" => '\n',
 }
 
-0x00.upto(0x1f) {|ch| C_ESC[[ch].pack("C")] ||= "\\x%02x" % ch }
-0x7f.upto(0xff) {|ch| C_ESC[[ch].pack("C")] = "\\x%02x" % ch }
+0x00.upto(0x1f) {|ch| C_ESC[[ch].pack("C")] ||= "\\%03o" % ch }
+0x7f.upto(0xff) {|ch| C_ESC[[ch].pack("C")] = "\\%03o" % ch }
 C_ESC_PAT = Regexp.union(*C_ESC.keys)
 
 def c_esc(str)