A valve arrangement is inserted between a master brake cylinder and a reservoir in a housing of an electrohydraulic motor vehicle brake system which can be activated both by a vehicle driver and independently of the vehicle driver. The valve arrangement can be acted on by a volume flow which can be conveyed by a linear actuator in the direction of a pedal travel simulator, the working chamber of the pedal travel simulator being connected to the master brake cylinder, wherein, for the purpose of simplified construction and actuation, the valve arrangement has a hydraulically actuable non-return valve and a fixed diaphragm arranged parallel to the non-return valve. The non-return valve is arranged together with the fixed diaphragm in a valve carrier which is fastened to a closure plug which closes the housing of the motor vehicle brake system.