diff --git a/testlib/dbus.py b/testlib/dbus.py
index 6c26d3c..40a07f5 100644
--- a/testlib/dbus.py
+++ b/testlib/dbus.py
@@ -256,7 +256,7 @@ def pool_start(id_string, id_type):
             StratisDbus._MNGR_IFACE,
         )
 
-        return manager_iface.StartPool(id_string, id_type, (False, ""))
+        return manager_iface.StartPool(id_string, id_type, (False, ""), (False, 0))
 
     @staticmethod
     def pool_stop(id_string, id_type):