diff --git a/lib/dynflow/dispatcher.rb b/lib/dynflow/dispatcher.rb
index 403f3662..92273575 100644
--- a/lib/dynflow/dispatcher.rb
+++ b/lib/dynflow/dispatcher.rb
@@ -30,7 +30,7 @@ module Dispatcher
       end
 
       Halt = type do
-        fields! execution_plan_id: String, optional: Algebrick::Types::Boolean
+        fields! execution_plan_id: String
       end
 
       variants Event, Execution, Ping, Status, Planning, Halt