The politicization of the European Union has elicited a variety of views on the European polity. Public scepticism is often directed at the European Commission which is accused of being an unresponsive and illegitimate bureaucracy. How does politicization affect the institutional role conceptions of Commission officials? By building on the literature of politicization and norm-guided open system approaches, I develop theoretical propositions on how politicization may affect the institutional role conceptions of Commission officials. Grounded on the proposition that Commission officials are most likely to respond to politicization in their home country, an exploratory case study of Dutch officials (21 in-depth interviews) was performed to flesh out the mechanisms at play. The findings tentatively reveal that, in varying degrees, most officials respond to politicization by adapting their institutional role conception into a more pragmatic direction, in which subsidiarity or legitimacy concerns are central.