Drawing on extensive ethnographic engagement with the social world of the UNESCO Convention for the Safeguarding of the Intangible Cultural Heritage, this Element explores the mainstreaming of sustainable development principles in the heritage field. It illustrates how, while deeply entwined in the UN standardizing framework, sustainability narratives are expanding the frontiers of heritage and unsettling conventional understandings of its social and political functions. Ethnographic description of UNESCO administrative practices and case studies explain how the sustainabilization of intangible cultural heritage entails a fundamental shift in perspective: heritage is no longer nostalgically regarded as a fragile relic in need of preservation but as a resource for the future with new purposes and the potential to address broader concerns and anxieties of our times, ranging from water shortages to mental health. This might ultimately mean that the safeguarding endeavor is no longer about us protecting heritage but about heritage protecting us.