diff --git a/lib/active_model/serializer/railtie.rb b/lib/active_model/serializer/railtie.rb
index 88a84d0f..88878a28 100644
--- a/lib/active_model/serializer/railtie.rb
+++ b/lib/active_model/serializer/railtie.rb
@@ -1,3 +1,4 @@
+require 'rails/railtie'
 module ActiveModel
   class Railtie < Rails::Railtie
     initializer 'generators' do |app|