diff --git a/lib/rdoc/ri/driver.rb b/lib/rdoc/ri/driver.rb
index c4d1dd03df..46b98e99b5 100644
--- a/lib/rdoc/ri/driver.rb
+++ b/lib/rdoc/ri/driver.rb
@@ -1468,7 +1468,7 @@ def render_method_comment out, method, alias_for = nil# :nodoc:
         out << method.comment
       end
       out << RDoc::Markup::BlankLine.new
-      out << RDoc::Markup::Paragraph.new("(this method is alias for #{alias_for.full_name})")
+      out << RDoc::Markup::Paragraph.new("(This method is an alias for #{alias_for.full_name}.)")
       out << RDoc::Markup::BlankLine.new
       out << alias_for.comment
       out << RDoc::Markup::BlankLine.new
diff --git a/test/test_rdoc_ri_driver.rb b/test/test_rdoc_ri_driver.rb
index f636c6346f..18dcb5b68a 100644
--- a/test/test_rdoc_ri_driver.rb
+++ b/test/test_rdoc_ri_driver.rb
@@ -260,7 +260,7 @@ def test_add_method_that_is_alias_for_original
         para('alias comment'),
         blank_line,
         blank_line,
-        para('(this method is alias for Qux#original)'),
+        para('(This method is an alias for Qux#original.)'),
         blank_line,
         para('original comment'),
         blank_line,