Single user to have lrw to all mailboxes

I have implemented a global acl:

• owner lrwstipkae INBOX.Spam owner lrwstipeka .Trash owner lrwsti INBOX.Trash owner lrw
• user=master-user@mydomain.com lrs
• owner lrwstipkae

But the master-user then loses all other permissions on his own mailbox, he is left only with: lrs

Any pointers on how to fix this?