Dutch-medium schools in Brussels traditionally cater to a Dutch-speaking minority, but they have recently seen a massive influx of pupils with a limited competence in Dutch. In order to face the resulting pedagogical and ideological challenges, many of these schools have intensified their efforts to remain Dutch enclaves in a predominantly Francophone city. In this article we discuss one Dutch-medium secondary school that positions itself as fairly severe in this regard. We will demonstrate, however, that teachers were generally drawn to a more friendly interpretation of their language policy as they reconciled monolingual expectations with multilingual pupils. Thus, although teachers agreed that a severe linguistic stance was important, they formulated various reasons for not adopting this stance relentlessly. And while pupils in principle could earn a ticket for not speaking Dutch, teachers often merely prefigured the possibility of sanctions, ignored the use of other languages to address other pressing matters, and occasionally recruited pupils' other linguistic skills as a pedagogical device -- without, however, reneging on their language political stance. We argue that these ambivalent strategies can be usefully explained as the outcome of negotiating dilemmatically related ideological concerns.