diff --git a/app/models/attachment.rb b/app/models/attachment.rb
index 892d5c3..da82088 100644
--- a/app/models/attachment.rb
+++ b/app/models/attachment.rb
@@ -309,7 +309,7 @@ class Attachment < ActiveRecord::Base
     just_filename = value.gsub(/\A.*(\\|\/)/m, '')
 
     # Finally, replace invalid characters with underscore
-    @filename = just_filename.gsub(/[\/\?\%\*\:\|\"\'<>\n\r]+/, '_')
+    just_filename.gsub(/[\/\?\%\*\:\|\"\'<>\n\r]+/, '_')
   end
 
   # Returns the subdirectory in which the attachment will be saved