A self-propelled vacuum cleaner has a main housing having a bottom wall formed with an aperture, floor-engaging wheels on the main housing, and a drive in the main housing for rotating the wheels and advancing the main housing in a normal horizontal travel direction. A module housing projecting through the aperture forms a brush compartment defining a downward directed suction opening having relative to the direction a leading edge and a trailing edge. The module housing is supported in the main housing for limited vertical movement of the module housing relative to the main housing. A brush in the module housing is engageable through the opening with a floor beneath the opening, and a blower in the module housing having an intake connected via a duct to the brush compartment for aspirating air through the opening and past the brush into the module housing.