diff --git a/stack.env b/stack.env
index 2512c12..f12b783 100644
--- a/stack.env
+++ b/stack.env
@@ -15,6 +15,6 @@ DB_NAME=kestra
 DB_USER=kestra
 DB_PASSWORD=CHANGE_ME
 
-# Kestra Authentication
-KESTRA_ADMIN_USER=admin
+# Kestra Authentication (username must be a valid email address)
+KESTRA_ADMIN_USER=admin@kestra.io
 KESTRA_ADMIN_PASSWORD=CHANGE_ME