diff --git a/ChangeLog b/ChangeLog
index d26cc67db2..4d513ac2fc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jun  9 22:53:49 2011  CHIKANAGA Tomoyuki  <nagachika00@gmail.com>
+
+	* test/ruby/test_thread.rb (TestThread#test_kill_thread_subclass):
+	  add test for Thread.kill with Thread subclass instance.
+
 Thu Jun  9 22:31:47 2011  CHIKANAGA Tomoyuki  <nagachika00@gmail.com>
 
 	* test/ruby/test_thread.rb (TestThread#test_kill_wrong_argument):
diff --git a/test/ruby/test_thread.rb b/test/ruby/test_thread.rb
index c2e592bb4b..524a4fd14c 100644
--- a/test/ruby/test_thread.rb
+++ b/test/ruby/test_thread.rb
@@ -305,6 +305,17 @@ class TestThread < Test::Unit::TestCase
     assert_raise(TypeError, bug4367) {
       Thread.kill(nil)
     }
+    o = Object.new
+    assert_raise(TypeError, bug4367) {
+      Thread.kill(o)
+    }
+  end
+
+  def test_kill_thread_subclass
+    c = Class.new(Thread)
+    t = c.new { sleep 10 }
+    assert_nothing_raised { Thread.kill(t) }
+    assert_equal(nil, t.value)
   end
 
   def test_exit