diff --git a/ChangeLog b/ChangeLog
index 78b710b7bb..9be4067211 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Sep  1 14:24:14 2008  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* test/ruby/test_transcode.rb (test_windows_31j): added.
+
 Mon Sep  1 14:00:04 2008  Yuki Sonoda (Yugui)  <yugui@yugui.jp>
 
 	* README.EXT (Data-types): fixed for current status.
diff --git a/test/ruby/test_transcode.rb b/test/ruby/test_transcode.rb
index d9728a2875..6f578f875d 100644
--- a/test/ruby/test_transcode.rb
+++ b/test/ruby/test_transcode.rb
@@ -365,6 +365,14 @@ class TestTranscode < Test::Unit::TestCase
     check_both_ways("\u795E\u6797\u7FA9\u535A", "\x90\x5F\x97\xD1\x8B\x60\x94\x8E", 'shift_jis') # 神林義博
   end
 
+  def test_windows_31j
+    check_both_ways("\u222A", "\x81\xBE", 'Windows-31J') # Union
+    check_both_ways("\uFFE2", "\x81\xCA", 'Windows-31J') # Fullwidth Not Sign
+    check_both_ways("\u2235", "\x81\xE6", 'Windows-31J') # Because
+    check_both_ways("\u2160", "\x87\x54", 'Windows-31J') # Roman Numeral One
+    check_both_ways("\u2170", "\xFA\x40", 'Windows-31J') # Small Roman Numeral One
+  end
+
   def test_euc_jp
     check_both_ways("\u3000", "\xA1\xA1", 'euc-jp') # full-width space
     check_both_ways("\u00D7", "\xA1\xDF", 'euc-jp') # ×