In the context of a rapid expansion of 'internationalized' schools around the world, and the subsequent demands for a teaching workforce, teachers are increasingly on the move. It is, however, no longer sufficient to represent international teacher mobility merely as a movement of predominantly English-speaking teachers who can deliver American, British, Canadian or Australian curricula. The increase in schools that offer bilingual and dual curricula has resulted in the mobility of local teachers who work alongside English-speaking ones. Although these schools are attractive to many international and local teachers, they also present certain professional, cultural and linguistic challenges. Drawing on the theory of practice architectures, this article identifies and discusses the relational tensions between foreign and local teachers as they grapple to build a new professional culture of collaboration ‐ one that demands the transformation of dispositions, professional knowledge, actions and judgements to 'fit in' to the internationalized school.