# see https://groups.google.com/forum/#!msg/mongoid/MaXFVw7D_4s/T3sl6Flg428J
if defined?(:BSON)
  module BSON
    class ObjectId
      def as_json(_options = {})
        to_s
      end

      def to_bson_key(encoded = ''.force_encoding(BINARY))
        to_s.to_bson_key(encoded)
      end
    end
  end
end