Interlock device between an ignition lock and a manual selector lever of an automatic gear-change transmission has a first latch element interacting with the ignition lock and a second latch element interacting with the manual selector lever. The two latch elements are connected by means of a flexible adjusting linkage for transmitting tensile and compressive forces so that only in the parking position of the manual selector lever is the ignition lock actuable into its position of rest which solely allows the ignition key to be removed and wherein the manual selector lever is blocked in its parking position when the ignition lock is in the position of the rest.