How does lawmaking work in personalist dictatorships? Assuming that legislative institutions established within power-sharing arrangements become costly for dictators to ignore and are consequently likely to affect lawmaking processes and outcomes, we argue that while legislatures in personalist dictatorships may approve most government initiatives, they can affect lawmaking via amendments, which signal factional disagreement and may prompt dictators to kill their own bills. We test this argument by analysing the performance of the Cortes under Franco’s regime in Spain. We find that while its members intervened only in a share of the legislative agenda, and rarely rejected government bills, they still introduced many consequential amendments that reduced the likelihood of bill enactment.