diff --git a/library/Icinga/Authentication/UserGroup/LdapUserGroupBackend.php b/library/Icinga/Authentication/UserGroup/LdapUserGroupBackend.php
index 65187dcd4..a25f8ad96 100644
--- a/library/Icinga/Authentication/UserGroup/LdapUserGroupBackend.php
+++ b/library/Icinga/Authentication/UserGroup/LdapUserGroupBackend.php
@@ -607,7 +607,7 @@ class LdapUserGroupBackend extends LdapRepository implements UserGroupBackendInt
 
         return $this
             ->setGroupBaseDn($config->base_dn)
-            ->setUserBaseDn($config->get('user_base_dn', $this->getGroupBaseDn()))
+            ->setUserBaseDn($config->get('user_base_dn', $defaults->get('user_base_dn', $this->getGroupBaseDn())))
             ->setGroupClass($config->get('group_class', $defaults->group_class))
             ->setUserClass($config->get('user_class', $defaults->user_class))
             ->setGroupNameAttribute($config->get('group_name_attribute', $defaults->group_name_attribute))