Normative theories of secession can be divided into two main types: primary-right theories and remedial-right theories. The question of international institutions is often deliberately left aside by primary-right theorists of secession as a separate, legal question. Primary-right theorists thus mostly remain agnostic about the role of international institutions in the context of secession. Remedial-right theorists of secession are more likely to consider the international legal order, but tend to think that our theories must adapt to it rather than the other way around. I show that both types of theories are mistaken and that the question of international institutions in the context of secession requires new philosophical attention. I argue for a normative account of secession based on non-domination, and show that securing non-domination in the context of secession requires international institutions.