An actuator includes: a housing, the housing having a first chamber and a second chamber, the second chamber having a round cross section; an electric motor arranged in the first chamber of the housing, the electric motor having a motor shaft; an actuating element; a gear mechanism arranged in the second chamber of the housing, the gear mechanism being connected, on an input side of the gear mechanism, to the motor shaft of the electric motor, and being connected, on an output side of the gear mechanism, to the actuating element; and a round cover configured to close the second chamber having the round cross section.