rack-attack: NameError uninitialized constant using threaded server

We are running: rack-attack 4.2.0 rails 4.2.5.1 MRI ruby 2.3.1 puma 3.8.2

We are sometimes seeing NameError uninitialized constant Rack::Attack::Request when threading is enabled in Puma. I suspect this has something to do with the fact that rack-attack is using autoload. I came across this GH issue which describes what we’re seeing. I was wondering if anyone else has encountered this kind of issue when running a multi-threaded web server.