diff --git a/lib/graphql/batch/setup_multiplex.rb b/lib/graphql/batch/setup_multiplex.rb
index ad1d392..fdbf1b0 100644
--- a/lib/graphql/batch/setup_multiplex.rb
+++ b/lib/graphql/batch/setup_multiplex.rb
@@ -14,7 +14,7 @@ def after_multiplex(multiplex)
     end
 
     module Trace
-      def initialize(executor_class:, **_rest)
+      def initialize(executor_class: nil, **_rest)
         @executor_class = executor_class
         super
       end