diff --git a/app/controllers/dois_controller.rb b/app/controllers/dois_controller.rb
index c3e587d6d..8202072c0 100644
--- a/app/controllers/dois_controller.rb
+++ b/app/controllers/dois_controller.rb
@@ -1,5 +1,6 @@
 require 'uri'
 require 'base64'
+require 'benchmark'
 
 class DoisController < ApplicationController
   include ActionController::MimeResponds