Abstract: The spout (1) comprises a spout part (3) with a spout opening (3a) and the spout also comprises a flange part (2) that is connected to the spout part (3), said flange part (2) having two faces, a fixing face (2k) and a rear face (2i). The fixing face (2k) is oriented towards the spout part (3) and is provided for fixing to a composite package (6). An oxygen-impermeable foil (8) lies on the rear face (2i) of the flange part (2) and is welded to the rear face (2i) such that the spout opening (3a) is sealed towards the rear face (2i) by the foil (8).