nginx: [emerg] "http" directive is not allowed here in /etc/nginx/sites-enabled/default:1

I'm new to NGINX and I'm trying to setup minimal working thing. So I trying to run aiohttp mini-app with nginx and supervisor (by [this][1] example). But I can't configure Nginx right and getting the following error: nginx: [emerg] "http" directive is not allowed here in /etc/nginx/sites-enabled/default:1 Here is full default.conf file: http { upstream aiohttp { # Unix domain servers server unix:/tmp/example_1.sock fail_timeout=0; server unix:/tmp/example_2.sock fail_timeout=0; server unix:/tmp/example_3.sock fail_timeout=0; server unix:/tmp/example_4.sock fail_timeout=0; } server { listen 80; client_max_body_size 4G; server example.com; location / { proxy_set_header Host $http_host; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_redirect off; proxy_buffering off; proxy_pass http://aiohttp; } } } It looks correct. `server` directive is in `http` as it should be. And http is parent directive. What I'm doing wrong? [1]: http://aiohttp.readthedocs.io/en/stable/deployment.html