diff --git a/lib/uri/mailto.rb b/lib/uri/mailto.rb
index cb8024f..83de2f7 100644
--- a/lib/uri/mailto.rb
+++ b/lib/uri/mailto.rb
@@ -266,18 +266,18 @@ def to_s
     #   # => "To: ruby-list@ruby-lang.org\nSubject: subscribe\nCc: myaddr\n\n\n"
     #
     def to_mailtext
-      to = URI.decode_www_form_component(@to)
+      to = URI.decode_uri_component(@to)
       head = ''
       body = ''
       @headers.each do |x|
         case x[0]
         when 'body'
-          body = URI.decode_www_form_component(x[1])
+          body = URI.decode_uri_component(x[1])
         when 'to'
-          to << ', ' + URI.decode_www_form_component(x[1])
+          to << ', ' + URI.decode_uri_component(x[1])
         else
-          head << URI.decode_www_form_component(x[0]).capitalize + ': ' +
-            URI.decode_www_form_component(x[1])  + "\n"
+          head << URI.decode_uri_component(x[0]).capitalize + ': ' +
+            URI.decode_uri_component(x[1])  + "\n"
         end
       end
 
diff --git a/test/uri/test_mailto.rb b/test/uri/test_mailto.rb
index 6cd3352..007f227 100644
--- a/test/uri/test_mailto.rb
+++ b/test/uri/test_mailto.rb
@@ -14,6 +14,14 @@ def uri_to_ary(uri)
     uri.class.component.collect {|c| uri.send(c)}
   end
 
+
+  def test_to_mailtext_preserves_literal_plus
+    uri = URI.parse("mailto:a+b@example.test?subject=a+b&body=x+y")
+
+    assert_equal("To: a+b@example.test\nSubject: a+b\n\nx+y\n", uri.to_mailtext)
+    assert_equal(uri.to_mailtext, uri.to_rfc822text)
+  end
+
   def test_build
     ok = []
     bad = []