In my nginx config, I have the line
add_header 'X-Custom-Header' 'example' always;
When I access the page with curl -I http://<path to page> it returns the header as x-custom-header rather than X-Custom-Header as typed.
While HTTP headers are case-insensitive, and so this is still valid, I take the view that I am perfectly capable of typing a header in lowercase if that's what I want; I would rather have nginx do what it's told rather than something vaguely along the lines of what I told it to do.
Is there a way to stop it downcasing headers?