diff --git a/dovecot.nix b/dovecot.nix
index 7d978f1..8b54d68 100644
--- a/dovecot.nix
+++ b/dovecot.nix
@@ -352,6 +352,7 @@ in {
           passdb {
             driver = ldap
             args = ${cfg.ldap-conf}
+            username_format = %n
           }
 
           # All users map to one actual system user