diff --git a/rootfs/etc/confd/templates/10-auth.conf.tmpl b/rootfs/etc/confd/templates/10-auth.conf.tmpl
index af48a5c..498385f 100644
--- a/rootfs/etc/confd/templates/10-auth.conf.tmpl
+++ b/rootfs/etc/confd/templates/10-auth.conf.tmpl
@@ -1,4 +1,4 @@
 auth_username_chars = {{getenv "ALLOWED_USERNAME_CHARS" "äöüabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@"}}
-auth_username_format ="%Lu"
+auth_username_format ="%Ln"
 auth_mechanisms = {{getenv "AUTH_MECHANISMS" "plain login oauthbearer xoauth2"}}
 !include auth-oauth2.conf.ext