The present invention relates to a brake system for a vehicle. The proposed brake system (1) comprises an actuation unit for actuating wheel brakes of the vehicle in a normal operating mode of the brake system (1). Further, the system (1) comprises a brake cylinder (2) for pressurizing the wheel brakes of the vehicle in an emergency operating mode of the brake system (1). The brake cylinder (2) comprises a brake cylinder housing (4) and a push rod (3) being displaceable within the brake cylinder housing (4) by operation of a brake pedal (5). The brake cylinder (2) further comprises a piston (14) movably arranged within the brake cylinder housing (4). The piston (14) has a first surface and a second surface opposite the first surface. A hydraulic chamber (11) is formed within the brake cylinder housing (4) between the first surface of the piston (14) and an inner surface of the brake cylinder housing (4). The hydraulic chamber (11) is configured for being selectively fluidly connected with the wheel brakes. The brake cylinder (2) further comprises an elastic simulator element (13) arranged between the second surface of the piston (14) and the push rod (3) for pedal feel simulation. The brake cylinder (2) further comprises a locking element (22) configured to selectively mechanically couple the push rod (3) with the piston (14) to provide a rigid connection between the push rod (3) and the piston (14) during the emergency operating mode.