diff --git a/templates/docker-compose.yml.twig b/templates/docker-compose.yml.twig
index 94e2e6ba2eae36692474f4945f9582d7ac99fbf3..60aaebf14c7d7a57b431242793b58beb2e71ada4 100644
--- a/templates/docker-compose.yml.twig
+++ b/templates/docker-compose.yml.twig
@@ -669,6 +669,7 @@ services:
       - '/etc/localtime:/etc/localtime:ro'
       - '{{ projectrootfiles }}/in/mysql/data:/var/lib/mysql:rw,delegated'
   in-app:
+    # After first startup, call "sudo chown -R 1500:1500 app" and start again.
     image: 'invoiceninja/invoiceninja:5'
     depends_on:
       - in-db