diff --git a/spec/dummy/config/initializers/session_store.rb b/spec/dummy/config/initializers/session_store.rb
index 3e5d710a5..56ba032b5 100644
--- a/spec/dummy/config/initializers/session_store.rb
+++ b/spec/dummy/config/initializers/session_store.rb
@@ -1,3 +1,4 @@
 # Be sure to restart your server when you modify this file.
+require 'action_dispatch/middleware/session/mongoid_store'
 
 Rails.application.config.session_store :mongoid_store, key: '_registrations_session'