Custom Rails Environment running as Production

I have a custom environment for my Rails 3.0 application running on Nginx. When trying to get the custom error pages (404 and 500) working, I face an issue: It seems Rails only uses public/500.html and public/404.html开发者_如何学Python when the environment is called "production" and since my custom environment is called something else (next) it's not using those files.

How can I tell Rails that "next" is really a production environment?