diff --git a/ChangeLog b/ChangeLog
index 84c3f8b221..b53afcb8e9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Mon Mar 27 20:12:23 2017  Anton Davydov  <mail@davydovanton.com>
+
+	* lib/uri/mailto.rb: Removed needless `return` and use `.`` instead of `::`
+	  with class method.
+	* test/uri/test_mailto.rb: Added tests for coverage.
+
 Mon Mar 20 06:35:08 2017  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ruby.c (process_options): convert -e script to the encoding
diff --git a/lib/uri/mailto.rb b/lib/uri/mailto.rb
index 7299550d3f..1494c3952b 100644
--- a/lib/uri/mailto.rb
+++ b/lib/uri/mailto.rb
@@ -84,7 +84,7 @@ module URI
     #    puts m3.to_s  ->  mailto:listman@example.com?subject=subscribe
     #
     def self.build(args)
-      tmp = Util::make_components_hash(self, args)
+      tmp = Util.make_components_hash(self, args)
 
       case tmp[:to]
       when Array
@@ -118,7 +118,7 @@ module URI
         end
       end
 
-      return super(tmp)
+      super(tmp)
     end
 
     #
@@ -187,7 +187,7 @@ module URI
         end
       end
 
-      return true
+      true
     end
     private :check_to
 
@@ -214,7 +214,7 @@ module URI
           "bad component(expected opaque component): #{v}"
       end
 
-      return true
+      true
     end
     private :check_headers
 
@@ -267,22 +267,22 @@ module URI
     #   # => "To: ruby-list@ruby-lang.org\nSubject: subscribe\nCc: myaddr\n\n\n"
     #
     def to_mailtext
-      to = parser.unescape(@to)
+      to = URI.decode_www_form_component(@to)
       head = ''
       body = ''
       @headers.each do |x|
         case x[0]
         when 'body'
-          body = parser.unescape(x[1])
+          body = URI.decode_www_form_component(x[1])
         when 'to'
-          to << ', ' + parser.unescape(x[1])
+          to << ', ' + URI.decode_www_form_component(x[1])
         else
-          head << parser.unescape(x[0]).capitalize + ': ' +
-            parser.unescape(x[1])  + "\n"
+          head << URI.decode_www_form_component(x[0]).capitalize + ': ' +
+            URI.decode_www_form_component(x[1])  + "\n"
         end
       end
 
-      return "To: #{to}
+      "To: #{to}
 #{head}
 #{body}
 "
diff --git a/test/uri/test_mailto.rb b/test/uri/test_mailto.rb
index c09b001e0f..e7d3142198 100644
--- a/test/uri/test_mailto.rb
+++ b/test/uri/test_mailto.rb
@@ -2,10 +2,7 @@
 require 'test/unit'
 require 'uri/mailto'
 
-module URI
-
-
-class TestMailTo < Test::Unit::TestCase
+class URI::TestMailTo < Test::Unit::TestCase
   def setup
     @u = URI::MailTo
   end
@@ -97,6 +94,11 @@ class TestMailTo < Test::Unit::TestCase
     ok[-1] << {:to => 'listman@example.com', :headers => [['subject', 'subscribe']]}
     ok[-1] << {:to => 'listman@example.com', :headers => [['subject', 'subscribe']]}
 
+    # mailto:listman@example.com?subject=subscribe
+    ok << ["mailto:listman@example.com?subject=subscribe"]
+    ok[-1] << {:to => 'listman@example.com', :headers => { 'subject' => 'subscribe' }}
+    ok[-1] << {:to => 'listman@example.com', :headers => 'subject=subscribe' }
+
     ok_all = ok.flatten.join("\0")
 
     # mailto:joe@example.com?cc=bob@example.com?body=hello   ; WRONG!
@@ -129,6 +131,56 @@ class TestMailTo < Test::Unit::TestCase
     assert_equal(ok_all, ok.flatten.join("\0"))
   end
 
+  def test_initializer
+    assert_raise(URI::InvalidComponentError) do
+      URI::MailTo.new('mailto', 'sdmitry:bla', 'localhost', '2000', nil,
+                      'joe@example.com', nil, nil, 'subject=Ruby')
+    end
+  end
+
+  def test_check_to
+    u = URI::MailTo.build(['joe@example.com', 'subject=Ruby'])
+
+    assert_raise(URI::InvalidComponentError) do
+      u.to = '#1@mail.com'
+    end
+
+    assert_raise(URI::InvalidComponentError) do
+      u.to = '@invalid.email'
+    end
+  end
+
+  def test_to_s
+    u = URI::MailTo.build([nil, 'subject=Ruby'])
+
+    u.send(:set_to, nil)
+    assert_equal('mailto:?subject=Ruby', u.to_s)
+
+    u.fragment = 'test'
+    assert_equal('mailto:?subject=Ruby#test', u.to_s)
+  end
+
+  def test_to_mailtext
+    results = []
+    results << ["To: ruby-list@ruby-lang.org\nSubject: subscribe\n\n\n"]
+    results[-1] << { to: 'ruby-list@ruby-lang.org', headers: { 'subject' => 'subscribe' } }
+
+    results << ["To: ruby-list@ruby-lang.org\n\nBody\n"]
+    results[-1] << { to: 'ruby-list@ruby-lang.org', headers: { 'body' => 'Body' } }
+
+    results << ["To: ruby-list@ruby-lang.org, cc@ruby-lang.org\n\n\n"]
+    results[-1] << { to: 'ruby-list@ruby-lang.org', headers: { 'to' => 'cc@ruby-lang.org' } }
+
+    results.each do |expected, params|
+      u = URI::MailTo.build(params)
+      assert_equal(expected, u.to_mailtext)
+    end
+
+    u = URI.parse('mailto:ruby-list@ruby-lang.org?Subject=subscribe&cc=myaddr')
+    assert_equal "To: ruby-list@ruby-lang.org\nSubject: subscribe\nCc: myaddr\n\n\n",
+      u.to_mailtext
+  end
+
   def test_select
     u = URI.parse('mailto:joe@example.com?cc=bob@example.com&body=hello')
     assert_equal(uri_to_ary(u), u.select(*u.component))
@@ -137,6 +189,3 @@ class TestMailTo < Test::Unit::TestCase
     end
   end
 end
-
-
-end
diff --git a/version.h b/version.h
index 1ba3808348..9efba7b446 100644
--- a/version.h
+++ b/version.h
@@ -1,10 +1,10 @@
 #define RUBY_VERSION "2.3.3"
-#define RUBY_RELEASE_DATE "2017-03-22"
-#define RUBY_PATCHLEVEL 259
+#define RUBY_RELEASE_DATE "2017-03-27"
+#define RUBY_PATCHLEVEL 260
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 3
-#define RUBY_RELEASE_DAY 22
+#define RUBY_RELEASE_DAY 27
 
 #include "ruby/version.h"