The present application discloses a centering aid for a container having a container trough, with an access opening, a container lid and a seal. In the closed state of the container, the seal is arranged between the container trough and the container lid. The centering aid has a first centering device, which is provided on either the container lid or the container trough, and a second centering device, which is provided on the other of either the container lid or the container trough. The first and second centering devices interact in such a way as to ensure that, in the closed state of the container, the seal is in contact with the container trough and with the container lid along the entire periphery of the access opening.