Lasting peace after civil war is difficult to establish. One promising way to ensure durable peace is by carefully designing civil war settlements. We use a single theoretical model to integrate existing work on civil war agreement design and to identify additional agreement provisions that should be particularly successful at bringing about enduring peace. We make use of the bargaining model of war which points to commitment problems as a central explanation for civil war. We argue that two types of provisions should mitigate commitment problems: fear-reducing and cost-increasing provisions. Fear-reducing provisions such as third-party guarantees and power-sharing alleviate the belligerents’ concerns about opportunism by the other side. Provisions such as the separation of forces make the resumption of hostilities undesirable by increasing the costs of further fighting. Using newly expanded data on civil war agreements between 1945 and 2005, we demonstrate that cost-increasing provisions indeed reduce the chance of civil war recurrence. We also identify political power-sharing as the most promising fear-reducing provision.