diff --git a/ChangeLog b/ChangeLog
index 5e06e8e2ef..d0f6f6b7c7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Sep  8 13:47:39 2008  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
+
+	* test/ruby/test_io.rb (TestIO#test_dup): add open in block.
+	  see [ruby-dev:35957].
+
 Mon Sep  8 07:09:42 2008  Tadayoshi Funaba  <tadf@dotrb.org>
 
 	* complex.c: some adjustments.
diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index 6b2dc3102d..35f575aa13 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -636,6 +636,10 @@ class TestIO < Test::Unit::TestCase
       assert_equal("", f2.read)
     end
 
+    proc do
+      open(__FILE__) # see Bug #493 [ruby-dev:35957]
+    end.call
+
     pipe2 do |r, w|
       assert_raise(Errno::EMFILE, Errno::ENFILE, Errno::ENOMEM) do
         r2, w2 = r.dup, w.dup