The mechanical timepiece movement with power reserve indication comprises at least one barrel system connected to a winding wheel of a differential gear and an unwinding wheel of the differential gear. An intermediate wheel of the differential gear is connected to a cam wheel set to drive it in rotation via a reducing stage. A rack, which acts on a power reserve indicator, is in contact with the cam wheel set. When the power reserve is at zero, a locking part of the rack comes into contact with a locking member to lock the movement at an unwinding output of the barrel system or in contact with the unwinding wheel of the differential gear.