Error when use alias for fields (or method) with ? at the end

[Elsopuro]

class UserSerializer < Blueprinter::Base
  identifier :id

  view :default do
    fields :valid?
  end
end

This OK

class UserSerializer < Blueprinter::Base
  identifier :id

  view :default do
    fields :valid?,  name: :isValid
  end
end

ArgumentError (comparison of Symbol with Hash failed)

Now i use alias in the model, but would not like alias isValid valid?