diff --git a/src/en/administration/install_docker.md b/src/en/administration/install_docker.md
index c7cc1f8..ceedc19 100644
--- a/src/en/administration/install_docker.md
+++ b/src/en/administration/install_docker.md
@@ -33,6 +33,7 @@ server {
 
     location / {
         proxy_pass http://localhost:LEMMY_PORT;
+        proxy_set_header Host $host;
         include proxy_params;
     }
 }
@@ -40,6 +41,8 @@ server {
 
 You should also setup TLS, for example with [Let's Encrypt](https://letsencrypt.org/). [Here's a guide for setting up letsencrypt on Ubuntu](https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-20-04).
 
+For federation to work, it is important that you do not change any headers that form part of the signature. This includes the `Host` header - you may need to refer to the documentation for your proxy server to pass through the `Host` header unmodified.
+
 ## Updating
 
 To update to the newest version, you can manually change the version in `docker-compose.yml`. Alternatively, fetch the latest version from our git repo: