In preparing future sustainable tourism workers, universities need to design curriculum that develop students' skills in critical thinking and foreseeing the implications of their actions with a sense of ethics and empathy. Research evidence indicates, however, that students often graduate without these skills. A possible reason for this may be the design of tourism curriculum based on weak conceptualisations of sustainability as opposed to strong sustainability. Another possible reason could be that educators are not successfully cultivating students' capabilities to think in more complex ways about sustainability nor do they adequately acknowledge the ways in which the students make sense of the concept. This paper highlights the need to examine the conceptualisations of sustainability currently being integrated into university undergraduate tourism courses. Further discussion proposes that an alternative curriculum approach, referred to as a learning study underpinned by variation theory, might improve students' understanding of sustainability.