In this paper, we place the issue of university activism in the context of constituent and constituted power. By this we mean the ever-present danger that activists' demands will be co-opted and concurrently deactivated. To mitigate this risk, we develop a set of conceptual tools that enables thinking about the activist university in terms of instituent praxis; that is, an open process of co-becoming of an institution and its actors through the continuous co-production of rules that drive their actions. Contrary to the view of the university as something instituted, the activist university that we propose emphasises the possibility of sustaining the process of acting and its underlying rules, rather than the result of the act. The activist university is understood here as a crack that leaves the instituted university open every time the self-production of its subject emerges by the self-transformation of the actors in the very course of their activities. We observe a chance for grounding instituent praxis in the ontological shift in thinking the activist university from being to co-becoming, as this will allow for reclaiming the future for the university and its broader ecology.