diff --git a/php/templates/containers.twig b/php/templates/containers.twig
index 25792712..9c1efa3a 100644
--- a/php/templates/containers.twig
+++ b/php/templates/containers.twig
@@ -210,6 +210,7 @@
                             Backed up will get all important data of your Nextcloud AIO instance like the database, your files and configuration files of the mastercontainer and else. <br /><br/>
                             The backup itself will use a tool that is called <a href="https://github.com/borgbackup/borg#what-is-borgbackup">BorgBackup<a/> which is a well-known server backup tool that efficiently backs up your files and encrypts them on the fly. <br /><br/>
                             Backups get created in the following directory on the host: {{ borg_backup_host_location }}/borg <br /><br/>
+                            Be aware that this solution does not back up files and folders that are mounted into Nextcloud using the external storage app. <br /><br/>
 
                             {% if isApacheStarting != true %}
                                 <form method="POST" action="/api/docker/backup" class="xhr">
diff --git a/readme.md b/readme.md
index 63f13559..a59c5900 100644
--- a/readme.md
+++ b/readme.md
@@ -117,6 +117,8 @@ Backups can be created and restored in the AIO interface using the buttons `Crea
 
 The backups itself get encrypted with an encryption key that gets shown to you in the AIO interface. Please save that at a safe place as you will not be able to restore from backup without this key.
 
+Be aware that this solution does not back up files and folders that are mounted into Nextcloud using the external storage app.
+
 Note that this implementation does not provide remote backups, for this you can use the [backup app](https://apps.nextcloud.com/apps/backup).
 
 ---