In an aggregate for supplying fuel from a fuel container to an internal combustion engine of a motor vehicle, a housing of a pressure wave-damping device, connected to an outlet of the pump of the aggregate, has an enclosed interior subdivided into two separate chambers by a diaphragm. The first chamber is connected to the outlet of the pump and has its own outlet whereas the second chamber has a damping spring accommodated therein. The housing is formed of two opposite shell portions positioned opposite to each other. A ring-shaped flange is provided, which is a portion of the housing, and which holds the peripheral edge of the diaphragm and embraces the rims of the shell portions of the housing.