diff --git a/CERTIFICATE.md b/CERTIFICATE.md
index c175d5e..0846b96 100644
--- a/CERTIFICATE.md
+++ b/CERTIFICATE.md
@@ -8,9 +8,10 @@ To issue a certificate:
 
 3. Issue the certificate:
    ```
-   docker compose exec acme mkdir /etc/ssl/<domain>
-   docker compose exec acme --issue --server letsencrypt -d <domain> --webroot /var/www/html/<domain>
-   docker compose exec acme --install-cert -d <domain> --key-file /etc/ssl/<domain>/key.pem --fullchain-file /etc/ssl/<domain>/fullchain.pem
+   export DOMAIN=<domain>
+   docker compose exec acme mkdir /etc/ssl/$DOMAIN
+   docker compose exec acme --issue --server letsencrypt -d $DOMAIN --webroot /var/www/html/$DOMAIN
+   docker compose exec acme --install-cert -d $DOMAIN --key-file /etc/ssl/$DOMAIN/key.pem --fullchain-file /etc/ssl/$DOMAIN/fullchain.pem
    ```
 
 4. Set certificates in your server .conf to this: