diff --git a/ChangeLog b/ChangeLog
index c60be0e434..17ad9812e2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Jul 27 02:06:55 2014  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
+
+	* lib/delegate.rb: split executable code into sample directory.
+	* sample/delegate.rb: ditto.
+
 Sun Jul 27 01:46:34 2014  Zachary Scott  <e@zzak.io>
 
 	* proc.c (method_super_method): [DOC] Method#super_method
diff --git a/lib/delegate.rb b/lib/delegate.rb
index be871090a7..f2b1388107 100644
--- a/lib/delegate.rb
+++ b/lib/delegate.rb
@@ -415,37 +415,3 @@ def DelegateClass(superclass)
   end
   return klass
 end
-
-# :enddoc:
-
-if __FILE__ == $0
-  class ExtArray<DelegateClass(Array)
-    def initialize()
-      super([])
-    end
-  end
-
-  ary = ExtArray.new
-  p ary.class
-  ary.push 25
-  p ary
-  ary.push 42
-  ary.each {|x| p x}
-
-  foo = Object.new
-  def foo.test
-    25
-  end
-  def foo.iter
-    yield self
-  end
-  def foo.error
-    raise 'this is OK'
-  end
-  foo2 = SimpleDelegator.new(foo)
-  p foo2
-  foo2.instance_eval{print "foo\n"}
-  p foo.test == foo2.test       # => true
-  p foo2.iter{[55,true]}        # => true
-  foo2.error                    # raise error!
-end
diff --git a/sample/delegate.rb b/sample/delegate.rb
new file mode 100644
index 0000000000..918dc08877
--- /dev/null
+++ b/sample/delegate.rb
@@ -0,0 +1,31 @@
+require 'delegate'
+
+class ExtArray<DelegateClass(Array)
+  def initialize()
+    super([])
+  end
+end
+
+ary = ExtArray.new
+p ary.class
+ary.push 25
+p ary
+ary.push 42
+ary.each {|x| p x}
+
+foo = Object.new
+def foo.test
+  25
+end
+def foo.iter
+  yield self
+end
+def foo.error
+  raise 'this is OK'
+end
+foo2 = SimpleDelegator.new(foo)
+p foo2
+foo2.instance_eval{print "foo\n"}
+p foo.test == foo2.test       # => true
+p foo2.iter{[55,true]}        # => true
+foo2.error                    # raise error!