University-based living labs serve as open innovation platforms that foster collaborative research and experimentation across various disciplines. These labs bring together academics, citizens, community organisations, companies, and other entities to collectively address complex contemporary issues. The labs' managers are expected to adopt flexible, agile management approaches to support the openness of their lab to stakeholders. Flexible management approaches create various challenges, as the labs are often expected also to comply with traditional project management principles of deadlines, project deliverables, budget restrictions, and quality conditions as set by their project sponsors and host organisation. The combination of prescriptive and agile project management approaches in such open innovation settings has been relatively underexplored in higher education research. Drawing on the theoretical literature on boundary work and project management, we analyse how the managers of a Dutch university-based living lab execute flexible project management styles in a setting that is dominated by prescriptive project management traditions. Based on information from 20 interviews and document analysis we identify five areas of tension between agile and prescriptive project management. Living lab managers, supported by researchers, buffer these tensions through boundary work that shapes the openness of the projects in rather unexpected ways.