vib.d suppress 404 for no content written

[Nicholas Wilson via Digitalmars-d-learn]

I have an endpoint that is a post:

void postStuff(HTTPServerRequest req, HTTPServerResponse res)
{
    // do some stuff with req
    res.statusCode = 200;
}
I do not write anything to res (deliberately) but want to set the 
status code.

However it returns 404, because no content is written.
How can I make it return 200?

FWIW its a member of a web interface class.

Thanks
Nic