A convolute for a bellows of a gangway, the convolute comprising a first rim and a second rim arranged next to the first rim; a sheet like convolute material that extends from the first rim to the second rim; whereby in an operational position of the convolute, the convolute material takes up a trough-shaped form between the first rim and the second rim; a drainage hole is defined in the convolute material; and a closure closes the drainage hole. The convolute further comprises a drainage control band, whereby the closure forms part of the drainage control band or is attached to the drainage control band, whereby a first band point of the drainage control band is attached to or rests on a first convolute point, whereby the first convolute point is located on the first rim or on the convolute material, but closer to the first rim than to the second rim, and a second band point of the drainage control band is attached to or rests on a second convolute point, whereby the second convolute point is located on the second rim or on the convolute material, but closer to the second rim than to the first rim. The length L1 of a minimum length band path, the minimum length band path being the path with the shortest length that can be taken from the first band point to the second band point while always staying in contact with or leading through the drainage control band, is smaller than the length L2 of a minimum length convolute path, the minimum length convolute path being the path with the shortest length that can be taken from the first convolute point to the second convolute point while always staying in contact with or leading through the convolute material.