diff --git a/ChangeLog b/ChangeLog
index 24259b74bb..dbd5e8ccc7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Jun 17 02:01:00 2006  Tanaka Akira  <akr@m17n.org>
+
+	* lib/pp.rb (Kernel#pretty_inspect): defined for pretty printed
+	  string.
+
 Sat Jun 17 00:23:58 2006  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* parse.y (reswords): kDO_BLOCK was missing.  fixed: [ruby-core:7995]
diff --git a/lib/pp.rb b/lib/pp.rb
index dc5856dab0..992369911d 100644
--- a/lib/pp.rb
+++ b/lib/pp.rb
@@ -46,8 +46,16 @@
 require 'prettyprint'
 
 module Kernel
+  # returns a pretty printed object as a string.
+  def pretty_inspect
+    PP.pp(self, '')
+  end
+
   private
-  def pp(*objs)
+  # prints arguments in pretty form.
+  #
+  # pp returns nil.
+  def pp(*objs) # :doc:
     objs.each {|obj|
       PP.pp(obj)
     }