Hey Rafael. Thanks for the review. I initially thought that is should always be a hash, but check out [this line](https://github.com/plataformatec/faraday-http-cache/blob/master/spec/storage_spec.rb#L18) in the spec. Since storage just passes the arguments to [lookup_store](http://api.rubyonrails.org/classes/ActiveSupport/Cache.html#method-c-lookup_store), `options` can also be a string.