diff --git a/README.md b/README.md
index 81575d2..ddcfcbd 100644
--- a/README.md
+++ b/README.md
@@ -67,6 +67,7 @@ consistency. These are generally cluster-level configuration.
 | `k3s_build_cluster`                  | When multiple play hosts are available, attempt to cluster. Read notes below.              | `true`                         |
 | `k3s_registration_address`           | Fixed registration address for nodes. IP or FQDN.                                          | NULL                           |
 | `k3s_github_url`                     | Set the GitHub URL to install k3s from.                                                    | https://github.com/k3s-io/k3s  |
+| `k3s_api_url`                        | URL for K3S updates API.                                                                   | https://update.k3s.io          |
 | `k3s_install_dir`                    | Installation directory for k3s.                                                            | `/usr/local/bin`               |
 | `k3s_install_hard_links`             | Install using hard links rather than symbolic links.                                       | `false`                        |
 | `k3s_server_config_yaml_d_files`     | A flat list of templates to supplement the `k3s_server` configuration.                     | []                             |