diff --git a/ChangeLog b/ChangeLog
index 81c42816d9..2ee61f99f3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Thu Mar  7 10:42:28 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* lib/thread.rb (Queue#push): return self.
+	* lib/thread.rb (Queue#clear): ditto.
+	* lib/thread.rb (SizedQueue#push): ditto.
+	* test/thread/test_queue.rb: add tests for the above.
+
 Thu Mar  7 10:40:49 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* tool/change_maker.rb (#diff2index): check Encoding::BINARY.
diff --git a/lib/thread.rb b/lib/thread.rb
index 1c8107085b..0bc95a2594 100644
--- a/lib/thread.rb
+++ b/lib/thread.rb
@@ -165,6 +165,7 @@ class Queue
         @que.push obj
         @cond.signal
       end
+      self
     end
   end
 
@@ -228,6 +229,7 @@ class Queue
   #
   def clear
     @que.clear
+    self
   end
 
   #
@@ -315,6 +317,7 @@ class SizedQueue < Queue
         @que.push obj
         @cond.signal
       end
+      self
     end
   end
 
diff --git a/test/thread/test_queue.rb b/test/thread/test_queue.rb
index 993514f86d..24465e03a1 100644
--- a/test/thread/test_queue.rb
+++ b/test/thread/test_queue.rb
@@ -108,4 +108,29 @@ class TestQueue < Test::Unit::TestCase
       end
     }
   end
+
+  def test_queue_push_return_value
+    q = Queue.new
+    retval = q.push(1)
+    assert_same q, retval
+  end 
+
+  def test_queue_clear_return_value
+    q = Queue.new
+    retval = q.clear
+    assert_same q, retval
+  end
+
+  def test_sized_queue_push_return_value
+    q = SizedQueue.new(1)
+    retval = q.push(1)
+    assert_same q, retval
+  end
+
+  def test_sized_queue_clear_return_value
+    q = SizedQueue.new(1)
+    retval = q.clear
+    assert_same q, retval
+  end
+
 end