diff --git a/authentik-container.nix b/authentik-container.nix
index 21620fc..9c74355 100644
--- a/authentik-container.nix
+++ b/authentik-container.nix
@@ -142,6 +142,8 @@ in {
 
           AUTHENTIK_SECRET_KEY = readFile authentikSecretKeyFile;
 
+          AUTHENTIK_DEFAULT_USER_CHANGE_USERNAME = toString false;
+
           AUTHENTIK_EMAIL__HOST = cfg.smtp.host;
           AUTHENTIK_EMAIL__PORT = toString cfg.smtp.port;
           AUTHENTIK_EMAIL__USERNAME = cfg.smtp.user;