diff --git a/lib/searchkick.rb b/lib/searchkick.rb
index d030823..3f9a204 100644
--- a/lib/searchkick.rb
+++ b/lib/searchkick.rb
@@ -207,4 +207,7 @@ end
 
 # TODO find better ActiveModel hook
 ActiveModel::Callbacks.send(:include, Searchkick::Model)
-ActiveRecord::Base.send(:extend, Searchkick::Model) if defined?(ActiveRecord)
+
+ActiveSupport.on_load(:active_record) do
+  extend Searchkick::Model
+end
--
libgit2 0.21.0