School choice is associated with increased educational inequality and across-school segregation. This article documents the organisational practices and logics affecting school segregation and inequality. Through an institutional ethnographic study of principals' responses to school choice within the context of immigration in Malmö, Sweden, I find that principals work to align their schools with generalised conceptions of a 'good' school -- a 'Swedish' school without many immigrants. Principals pursue the image or reality of 'Swedishness' through choices about the presentation of the school, approaches to managing enrolment, selection of programmes of study, and even decisions about where schools are located. Through their administrative work, principals write presumed preferences for Swedishness into the structure of the school system. The results suggest that, when addressing the link between school choice and equality, group preferences of school choosers cannot be considered independently of the organisation of schooling accomplished by principals and other organisational actors.