diff --git a/README.md b/README.md
index fb2a4b9..2417949 100644
--- a/README.md
+++ b/README.md
@@ -80,6 +80,7 @@ and especially have a look at [this section of the haproxy.cfg](https://codeberg
 - `ENABLE_HTTP_SERVER` (default: false): Set this to true to enable the HTTP-01 challenge and redirect all other HTTP requests to HTTPS. Currently only works with port 80.
 - `DNS_PROVIDER` (default: use self-signed certificate): Code of the ACME DNS provider for the main domain wildcard.  
   See <https://go-acme.github.io/lego/dns/> for available values & additional environment variables.
+- `NO_DNS_01` (default: `false`): Disable the use of ACME DNS. This means that the wildcard certificate is self-signed and all domains and subdomains will have a distinct certificate. Because this may lead to a rate limit from the ACME provider, this option is not recommended for Gitea/Forgejo instances with open registrations or a great number of users/orgs.
 - `LOG_LEVEL` (default: warn): Set this to specify the level of logging.
 
 ## Contributing to the development