diff --git a/drivers/place/room_booking_approval.cr b/drivers/place/room_booking_approval.cr
index 617b869325..daad3a2039 100644
--- a/drivers/place/room_booking_approval.cr
+++ b/drivers/place/room_booking_approval.cr
@@ -153,7 +153,9 @@ class Place::RoomBookingApproval < PlaceOS::Driver
   # Multiple calls within the 10-second window are batched into a
   # single poll_events call per affected system, giving the calendar
   # provider time to propagate the status change.
-  protected def refresh_bookings(system_ids : Array(String))
+  # The exec runtime waits on any returned task, so this must not return
+  # the scheduled one.
+  protected def refresh_bookings(system_ids : Array(String)) : Nil
     return if @disable_refresh_bookings
     @pending_refresh.concat(system_ids)
     return if @refresh_scheduled
diff --git a/drivers/place/room_booking_approval_spec.cr b/drivers/place/room_booking_approval_spec.cr
index 23e295a3b3..c9edce0483 100644
--- a/drivers/place/room_booking_approval_spec.cr
+++ b/drivers/place/room_booking_approval_spec.cr
@@ -314,15 +314,20 @@ DriverSpecs.mock_driver "Place::RoomBookingApproval" do
 
   poll_before = system(:Bookings_1)[:poll_events_calls].as_i
 
+  # The exec must respond before the debounce fires, not wait for it.
+  started = Time.monotonic
   exec(:accept_event,
     calendar_id: "room5@example.com",
     event_id: "tentative-event-1",
   ).get
+  (Time.monotonic - started).should be < 5.seconds
 
+  started = Time.monotonic
   exec(:decline_event,
     calendar_id: "room5@example.com",
     event_id: "tentative-event-4",
   ).get
+  (Time.monotonic - started).should be < 5.seconds
 
   sleep 11