diff --git a/plugins/commands/serve/mappers/machine.rb b/plugins/commands/serve/mappers/machine.rb
index 281b41770..e619e8ecf 100644
--- a/plugins/commands/serve/mappers/machine.rb
+++ b/plugins/commands/serve/mappers/machine.rb
@@ -64,7 +64,7 @@ module VagrantPlugins
 
         def converter(target)
           m = target.to_machine
-          Vagrant::Machine.new(nil, nil, nil, {}, {}, nil, nil, nil, nil, nil, base=false, client=m)
+          Vagrant::Machine.new(nil, nil, nil, nil, nil, nil, nil, nil, nil, base=false, client: m)
         end
       end