An automatic winding device for a spring of a watch movement including a weight fixed on a support via a bearing including a ring which drives, in only one direction of rotation called the winding direction, a transmission gear in order to wind the mainspring, this winding device wherein, on the one hand, the bearing is of the one-way type and blocks the rotation of the weight in the opposite direction to the winding direction, called the blocking direction and wherein, on the other hand, the device includes a means for decoupling the weight from said bearing in at least the blocking direction when the weight exerts on the bearing a torque higher than a desired value.