diff --git a/postfix.nix b/postfix.nix
index 8fa2924..f4bd48f 100644
--- a/postfix.nix
+++ b/postfix.nix
@@ -205,6 +205,11 @@ in {
             args = ${cfg.ldap-conf}
           }
 
+          userdb {
+            driver = ldap
+            args = ${cfg.ldap-conf}
+          }
+
           service auth {
             unix_listener auth {
               mode = 0600