In this article, I argue that any success a discourse on cosmopolitan hospitality might have in global citizenship education depends on how it deals with its own limits, and I propose a way of responding to these limits that takes the cosmopolitan commitment to openness to the other seriously. Following Jacques Derrida, my point is that to teach global citizenship on the basis that we already can know who the other is risks counting some persons "in" while leaving others "out", which forecloses the possibility of welcoming something new and unforeseen at the limit of our cosmopolitan selves.