The aim of this article is to complement research on transformations towards sustainability by drawing upon the innovation systems (IS) framework. The IS framework already serves as a suitable and influential basis for research on processes of technological innovation and economic change. We argue that improving the capacity of an IS framework for dealing with wicked problems and the normative complexity of sustainability requires a fundamental paradigm shift because in the current IS paradigm innovations are considered as per se desirable and in mostly technological terms. Therefore, we call for IS dedicated to transformations towards sustainability by opening up for systemic innovations beyond the technological dimension and by acknowledging that stakeholders have conflicting visions, interests, norms, and expectations with regard to sustainability goals. Taking the normative dimension of transformations towards sustainability seriously thus requires more explicit and integrative research on directionality, legitimacy, responsibility, and their interrelation in IS. The article concludes by proposing suggestions for future research based on IS-related approaches that can serve as building blocks for an IS framework capable of incorporating legitimate goal-orientation for transformative innovation by and for society.