Under what conditions do states and insurgents cooperate in providing rebel governance? Scholars have explored why and how insurgents provide rebel governance. Less attention has been given the conditions that foster state-insurgent cooperation on governance in rebel-held areas. State-insurgent cooperation on rebel governance is puzzling because it can alienate hardliners, undermine legitimacy-seeking through governance, reveal sensitive information, and cause a loss of autonomy. We propose that the conflict parties are more likely to discount these costs when they have overlapping civilian constituencies that have high expectations for governance provision. Analysing state-insurgent cooperation on rebel governance in insurgent-controlled Côte d’Ivoire and Sri Lanka using original interview and archival data, we find support for the proposition that civilian expectations prompt state-insurgent cooperation, even when the parties appeal to separate constituencies. The study contributes to broaden our understanding of civil war dynamics and nuance existing theories of rebel governance, and concludes that civilians can play a critical role in shaping rebel rule.