Having been the scene of language planning for more than a century in relation to the two competing written standards of Norwegian, Norwegian language planners are now facing a new challenge: how to deal with what has been termed "domain loss" where Norwegian is perceived as losing out to English in important sectors of society, including higher education. Despite being widely used in public debate, in policy documents and in survey research, the concept of "domain loss" is currently under-theorised. As the present study of linguistic practices in an English-medium MSc programme shows, practice is complex and multilingual and includes code-switching in a way that the term "domain loss" or language planning policies do not fully capture. The paper thus attempts to bridge the gap between research on code-switching in the tradition of Peter Auer on the one hand and research on domain loss and language planning on the other.