In recent times, there has been a strong focus on moving university teaching away from a so-called 'instructivist', lecture-centred mode, in which the focus is on what teachers are doing, towards a more student-centred 'constructivist' approach, centred on active learning and students' own constructions of knowledge. This paper considers the tensions and challenges raised by the ways in which constructivist ideas are being taken up in higher education, highlighting two particular issues (1) the positioning of curriculum knowledge as settled and easily transferable across modes of teaching; and (2) the neglect of important disciplinary differences as a result. These issues are explored in relation to two particular case studies of universities introducing new online learning reforms. These case studies show the problems potentially raised by the limited attention to curriculum in the push for more constructivist pedagogies, including a limited interpretation of what constructivist teaching entails and an inattention to the conditions required for its practice.