You're still getting a 418 response there, just not the right status description. Varnish is certainly stuffing us up a bit. There's a note about this at the b

You're still getting a 418 response there, just not the right status description. Varnish is certainly stuffing us up a bit. There's a note about this at the bottom of the page. If I did this again, I wouldn't deploy it to Heroku for this reason.