International law and the work of international organisations have significantly normalised the attribution of a (binary) legal gender to individuals. This has fostered state-building processes and facilitated the codification of hetero-patriarchy and cisnormativity in the law. Looking at recent trends in international law and international organisations, the author argues that gender (identity) is increasingly treated as a private property that is owned by individuals and legitimately creates capital. This reflects a liberal rights logic, ignoring that legal gender categories are never valuable in themselves, but that they become valuable through surrounding social and legal relations. The thesis thus contemplates ways to “de-propertize” legal gender by lowering their importance for the accumulation of economic, symbolic, and political capital. Assemblage thinking is thereby used as method to understand how legal gender categories become valuable through the entanglement of norms from different normative orders and their interrelationship with other social categories, such as race and class. It serves as a queer-feminist method in international studies that reflects feminist concerns about difference and universalism as well as the idea of law as a system of relations.