A mold for a machine which is used for the blow molding of containers from performs. The inventive mold includes a wall defining a cavity that is intended to receive a preform. In addition, the mold includes at least one mold insert which is equipped with a lug and which is mounted such that it can move in relation to the wall by means of a cam system, between: an out position in which the lug projects out at least partially from the wall into the cavity, and a retracted position in which the lug is retracted into the wall. The invention also relates to a method of producing a container by means of blow molding using one such mold.