return 404 from map module default value

[zflairz]

I'm using map module to redirect URLs which have been removed (but
indexed by search engine).
But how can I fall back to http 404 response for urls not present in my
redirect list?

I've tried following, but I got 200 instead of 404:

        location ~* ^/404$ {
                return 404;
        }

        error_page 404 = /404.html;

        map $uri $redirected_uri {
                default /404; #here?
                include /etc/nginx/redirected_uri.txt;
        }

        location ~* ^/.+ {
                if (!-f $request_filename) {
                        rewrite ^ $redirected_uri permanent;
                }
        }

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,213431,213431#msg-213431