diff --git a/cylc/flow/network/schema.py b/cylc/flow/network/schema.py
index f86ba15f567..8cbcdae610b 100644
--- a/cylc/flow/network/schema.py
+++ b/cylc/flow/network/schema.py
@@ -833,7 +833,6 @@ class Meta:
             messages. It is down to the client to store / preserve previous
             records.
         '''),
-        default_value=[],
     )