diff --git a/ChangeLog b/ChangeLog
index fb0fb64a05..5e2afaa1c0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Nov 14 13:27:03 2004  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/pp.rb (PP#object_address_group): remove odd number of 'f'
+	  prefixed to negative address.
+
 Sun Nov 14 08:51:04 2004  NAKAMURA, Hiroshi  <nakahiro@sarion.co.jp>
 
 	* test/logger/test_logger.rb: Logger just expects
diff --git a/lib/pp.rb b/lib/pp.rb
index 6ddd4dd2eb..756dce6f51 100644
--- a/lib/pp.rb
+++ b/lib/pp.rb
@@ -219,7 +219,9 @@ class PP < PrettyPrint
     end
 
     def object_address_group(obj, &block)
-      group(1, "\#<#{obj.class}:#{("0x%x" % (obj.__id__ * 2)).sub(/\.\.f/, '')}", '>', &block)
+      id = "%x" % (obj.__id__ * 2)
+      id.sub!(/\Af(?=[[:xdigit:]]{2}+\z)/, '') if id.sub!(/\A\.\./, '')
+      group(1, "\#<#{obj.class}:0x#{id}", '>', &block)
     end
 
     def comma_breakable