Only getting 10.0.0.1 when connecting via IPv6

[frlan]

Having

    location / {
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $http_x_real_ip;
        proxy_set_header REMOTE_ADDR $http_x_real_ip;
	proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header X-Forwarded-Proto $scheme;
       …

inside Nginx configuration the logging of IPv4 works well.

But when the remote host is connecting via IPv6 logging is falling back to the default 10.0.0.1. It would be awesome, if IPv6 would be also supported (maybe just using the /64). (Or am I having an configuration issue here?)