diff --git a/ChangeLog b/ChangeLog
index dbfa7c28b2..32df37baaf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Dec  6 18:56:42 2010  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
+
+	* test/ruby/test_string.rb (TestString#test_scan): add a test for
+	  [ruby-core:33338] #4087.
+
 Mon Dec  6 18:55:36 2010  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
 
 	* test/uri/test_common.rb (TestCommon#test_encode_www_form): add
diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index e8287622f6..16a6905667 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -968,6 +968,14 @@ class TestString < Test::Unit::TestCase
     res = []
     a.scan(/(...)/) { |w| res << w }
     assert_equal([[S("cru")], [S("el ")], [S("wor")]],res)
+
+    a = S("hello")
+    a.taint
+    a.untrust
+    res = []
+    a.scan(/./) { |w| res << w }
+    assert(res[0].tainted?, '[ruby-core:33338] #4087')
+    assert(res[0].untrusted?, '[ruby-core:33338] #4087')
   end
 
   def test_size