The invention relates to a closing plate (3) for a windscreen wiper drive motor device (1) for a motor vehicle, said device (1) being of the type comprising a support (2), a shaft (5) being received therein, said shaft bearing an endless screw (6) which is capable of being driven in rotation by a motor (7), and being of the type in which said support (2) comprises a bush mounting (17) for receiving a bush (18) which is capable of supporting one end (5a) of the shaft (5), said plate (3) comprising a base (14) which is capable of closing said support (2), the closing plate (3) being characterized in that it comprises a closing tongue (20) which is made of the same material as the base (14) and serves as a water deflector for an orifice (19) formed in the end of the bush mounting (17) in the axis of rotation of the shaft (5). The inventor further relates to a windscreen wiper drive motor device for a motor vehicle comprising a closing plate.