An interlocking device for the folding roof of a motor vehicle with a locking hook (4) which is pivotally mounted on the front frame part (1) of the folding roof and which can be moved by means of a multiple connecting rod mechanism and can be interlocked in latching engagement on a vehicle-mounted abutment, the multiple connecting rod mechanism, especially a four-bar mechanism (6, 12, 14, 15), containing the locking hook (4) and being located self-locking in the closed position.