diff --git a/ChangeLog b/ChangeLog
index 68e1bab457..2c2d5dab76 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Dec  7 21:06:38 2010  Kouhei Sutou  <kou@cozmixng.org>
+
+	* lib/rexml/doctype.rb, test/rexml/test_doctype.rb: suppress warnings.
+	  [ruby-core:33305]
+	  Reported by Aaron Patterson. Thanks!!!
+
 Tue Dec  7 18:56:52 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* ext/nkf/lib/kconv.rb (String#kconv): fix typo and update rdoc.
diff --git a/lib/rexml/doctype.rb b/lib/rexml/doctype.rb
index 678095ae28..0b3c533bb4 100644
--- a/lib/rexml/doctype.rb
+++ b/lib/rexml/doctype.rb
@@ -248,11 +248,11 @@ module REXML
     end
 
     def to_s
-      "<!NOTATION #@name #@middle#{
-        @public ? ' ' + public.inspect : ''
-      }#{
-        @system ? ' ' +@system.inspect : ''
-      }>"
+      notation = "<!NOTATION #{@name} #{@middle}"
+      notation << " #{@public.inspect}" if @public
+      notation << " #{@system.inspect}" if @system
+      notation << ">"
+      notation
     end
 
     def write( output, indent=-1 )
diff --git a/test/rexml/test_doctype.rb b/test/rexml/test_doctype.rb
index f40f833d07..20603f5378 100644
--- a/test/rexml/test_doctype.rb
+++ b/test/rexml/test_doctype.rb
@@ -65,3 +65,43 @@ class TestDocTypeAccessor < Test::Unit::TestCase
   end
   
 end
+
+class TestNotationDeclPublic < Test::Unit::TestCase
+  def setup
+    @name = "vrml"
+    @id = "VRML 1.0"
+    @uri = "http://www.web3d.org/"
+  end
+
+  def test_to_s
+    assert_equal("<!NOTATION #{@name} PUBLIC \"#{@id}\">",
+                 decl(@id, nil).to_s)
+  end
+
+  def test_to_s_with_uri
+    assert_equal("<!NOTATION #{@name} PUBLIC \"#{@id}\" \"#{@uri}\">",
+                 decl(@id, @uri).to_s)
+  end
+
+  private
+  def decl(id, uri)
+    REXML::NotationDecl.new(@name, "PUBLIC", id, uri)
+  end
+end
+
+class TestNotationDeclSystem < Test::Unit::TestCase
+  def setup
+    @name = "gif"
+    @id = "gif viewer"
+  end
+
+  def test_to_s
+    assert_equal("<!NOTATION #{@name} SYSTEM \"#{@id}\">",
+                 decl(@id).to_s)
+  end
+
+  private
+  def decl(id)
+    REXML::NotationDecl.new(@name, "SYSTEM", id, nil)
+  end
+end