diff --git a/README.md b/README.md
index 76373d5..a479cb2 100644
--- a/README.md
+++ b/README.md
@@ -123,6 +123,7 @@ services:
       - SYMFONY__ENV__MAILER_USER=~
       - SYMFONY__ENV__MAILER_PASSWORD=~
       - SYMFONY__ENV__FROM_EMAIL=wallabag@example.com
+      - SYMFONY__ENV__DOMAIN_NAME=your-wallabag-url-instance.com
     ports:
       - "80"
     volumes: