Why do autocratic leaders resort to referenda to create a new constitution or amend an existing one? While the need to legitimize autocratic goals is rationally understandable and has received widespread scholarly attention, little is known about constitutional referenda as a tool to pursue this goal. A constitutional referendum puts the question about a decrease of parliamentary oversight, institutional accountability or just the plain abolishment of term limits to the people. If successful, the autocratic leader turns this plebiscite into the servant of autocratization. This poses an interesting theoretical and empirical puzzle. Through a comparative analysis of constitutional referenda in non-democratic countries, I show that they are primarily used when the constitution requires the autocratic leader to do so and that the existence of a hegemonic party significantly reduces the requirement for constitutional referenda.