diff --git a/config/routes.rb b/config/routes.rb
index ad83deac0..89927bee3 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -316,7 +316,7 @@ Rails.application.routes.draw do
 
   # additional routes for having the file name at the end of url
   get 'attachments/:id/:filename', :to => 'attachments#show', :id => /\d+/, :filename => /.*/, :as => 'named_attachment', :format => 'html'
-  get 'attachments/download/:id/:filename', :to => 'attachments#download', :id => /\d+/, :filename => /.*/, :as => 'download_named_attachment', format: 'html'
+  get 'attachments/download/:id/:filename', :to => 'attachments#download', :id => /\d+/, :filename => /.*/, :as => 'download_named_attachment', :format => 'html'
   get 'attachments/download/:id', :to => 'attachments#download', :id => /\d+/
   get 'attachments/thumbnail/:id(/:size)', :to => 'attachments#thumbnail', :id => /\d+/, :size => /\d+/, :as => 'thumbnail'
   resources :attachments, :only => [:show, :update, :destroy]