A locking arrangement for the openable top of an open automobile, in an open automobile provided with a multiple-articulated roof mechanism (1), by which the car top can be moved with the aid of an actuator into opened, respectively closed, position, and in which to the foremost, or first, rib (2) on the free end of the car top has been connected a first locking member (3) and on the windshield beam (4) has been provided a second locking member (5), said locking members in mutual cooperation locking the car top to the windshield beam when the car top is in closed position. The roof mechanism (1) has been arranged to guide the motion path of the first rib (2) on the free end of the car top at the terminal stage of the closing motion in the vicinity of the windshield beam (4) to be substantially longitudinal to the vehicle or at a small angle somewhat downward inclined from the horizontal plane, and the locking members (3 and 5) are disposed to become interlocked so that exclusively said terminal motion of the roof mechanism causes automatic interlocking of the first locking member (3) with the second locking member (5) on the windshield beam.