ActiveModelSerializers.config.serializer_lookup_chain.unshift(
  lambda do |resource_class, serializer_class, namespace|
    # Maps Foo::Bar to FooSerializer
    parent_module_name = resource_class.name.deconstantize
    [serializer_class, namespace].map do |m|
      "#{m}::#{parent_module_name}Serializer"
    end
  end
)