Accounting for our knowledge of de re modalities is probably the main reason why the proponents of modal empiricism think that their view should be preferred to modal rationalism. In this paper, I address Sonia Roca-Royes’ account, which is taken to be a representative modal empiricist view, in order to show that modal empiricism faces serious problems even in explaining our knowledge of possibility de re, something which seems to be the easiest thing to explain on this view. I argue that Roca-Royes’ account does not prove what she claims it does, that it can hardly be articulated in a non-redundant way, and that her account of our knowledge of possibility de re can hardly be reconciled with the essentiality of origin principle, to which modal empiricists sometimes appeal while criticizing the modal rationalist account.