Abstract: A brake device is described for braking the wheels of a vehicle. The brake device includes at least one brake master cylinder, a brake booster, a wheel brake, a return pump, using which a hydraulic fluid may be pumped back from the wheel brake in the direction of brake master cylinder. A sensor system for detecting an abrupt negative change in the friction coefficient of the roadway is provided. An arrangement is provided according to which the boost of the brake booster is set to a smaller value if a braking maneuver has been detected on a roadway having an abrupt negative change in the friction coefficient than in the case of a braking maneuver on a roadway without an abrupt negative change in the friction coefficient.