diff --git a/piker/clearing/_ems.py b/piker/clearing/_ems.py
index 3756daf4..1567f795 100644
--- a/piker/clearing/_ems.py
+++ b/piker/clearing/_ems.py
@@ -1054,7 +1054,7 @@ async def _emsd_main(
 
             # signal to client that we're started and deliver
             # all known pps and accounts for this ``brokerd``.
-            await ems_ctx.started((pp_msgs, relay.accounts))
+            await ems_ctx.started((pp_msgs, list(relay.accounts)))
 
             # establish 2-way stream with requesting order-client and
             # begin handling inbound order requests and updates