diff --git a/ChangeLog b/ChangeLog
index 1cf391c8dd..1b23847c34 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Wed Oct 15 07:00:14 2014  Eric Wong  <e@80x24.org>
+
+	* test/ruby/test_optimization.rb (test_string_size): new test
+
 Wed Oct 15 06:51:13 2014  Eric Wong  <e@80x24.org>
 
 	* test/ruby/test_optimization.rb (test_string_eq_neq): new test
diff --git a/test/ruby/test_optimization.rb b/test/ruby/test_optimization.rb
index 2f9c0f6d22..129f62a0ff 100644
--- a/test/ruby/test_optimization.rb
+++ b/test/ruby/test_optimization.rb
@@ -87,6 +87,11 @@ class TestRubyOptimization < Test::Unit::TestCase
     assert_redefine_method('String', 'length', 'assert_nil "string".length')
   end
 
+  def test_string_size
+    assert_equal 6, "string".size
+    assert_redefine_method('String', 'size', 'assert_nil "string".size')
+  end
+
   def test_string_empty?
     assert_equal true, "".empty?
     assert_equal false, "string".empty?