diff --git a/internal/config/defaults.go b/internal/config/defaults.go
index f140d7877..cb8d08e35 100644
--- a/internal/config/defaults.go
+++ b/internal/config/defaults.go
@@ -70,6 +70,7 @@ var Defaults = Configuration{
 	InstanceSubscriptionsProcessFrom:  "23:00",        // 11pm,
 	InstanceSubscriptionsProcessEvery: 24 * time.Hour, // 1/day.
 	InstanceAllowBackdatingStatuses:   true,
+	InstanceAllowEmptyUserAgents:      false,
 
 	AccountsRegistrationOpen:         false,
 	AccountsReasonRequired:           true,