the invention relates to a plastic closure for malleable containers , comprising a spout having an outside thread and a terminal flange for fastening to the container and a cap which has an inside thread and can be screwed onto the outside thread of the spout in a closable manner , characterized in that the spout is directly or indirectly operatively connected to a membrane which reduces the flow and has at least one perforation , wherein in the usage position the membrane runs at least approximately in the region of the flange and parallel thereto .