diff --git a/lib/paperclip/attachment.rb b/lib/paperclip/attachment.rb
index 80480f650..07c1a4c84 100644
--- a/lib/paperclip/attachment.rb
+++ b/lib/paperclip/attachment.rb
@@ -127,7 +127,7 @@ def self.interpolations
           File.extname(attachment.original_filename).gsub(/^\.+/, "")
         end,
         :id         => lambda{|attachment,style| attachment.instance.id },
-        :attachment => lambda{|attachment,style| attachment.name.pluralize },
+        :attachment => lambda{|attachment,style| attachment.name.to_s.pluralize },
         :style      => lambda{|attachment,style| style || attachment.default_style },
       }
     end
diff --git a/test/helper.rb b/test/helper.rb
index 4191afcb0..7b33d2167 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -23,14 +23,6 @@ def pluralize
   end
 end
 
-class Symbol
-  unless methods.include? :pluralize
-    def pluralize
-      "#{self}s"
-    end
-  end
-end
-
 FIXTURES_DIR = File.join(File.dirname(__FILE__), "fixtures") 
 config = YAML::load(IO.read(File.dirname(__FILE__) + '/database.yml'))
 ActiveRecord::Base.logger = Logger.new(File.dirname(__FILE__) + "/debug.log")