It has been highlighted how design engagement with the public sector risks being either irrelevant or instrumental to technocratic agendas due to a lack of understanding of the public sector’s nature. Based on the idea of public sector innovation as a matter of learning and adaptation for continuous improvement, this article looks at how participatory design approaches can be used to drive co-learning processes within the public sector, namely, collaborative learning processes about institutional aspects. It reflects on the authors’ engagement within a Swedish public organisation that relied on traditional design processes and co-learning processes. By analysing these processes, the article highlights how design as problem framing, by supporting collaborative reflexivity, can be a fruitful way to engage with institutional aspect.