diff --git a/lib.nix b/lib.nix
index 586ae93..479a5da 100644
--- a/lib.nix
+++ b/lib.nix
@@ -68,6 +68,7 @@ in
       package ? pkgs.postgresql,
       port ? 5432,
       listen_addresses ? "localhost",
+      initialDatabases ? [ ],
       ...
     }:
     let