A closing mechanism for the trap door of a stone trap mounted in the floor of the feeder house on a combine harvester is disclosed wherein the trap door can be moved from a opened position to a closed position by the raising of the header. If the stone trap door has been opened for the ejection of non-crop material within the flow of crop material within the feeder house, a link interconnecting the trap door and the frame of the combine effects a pivotal movement of the trap door to its closed position upon actuation of the header lift cylinders to raise the feeder house and attached header above the ground. The link includes a spring to permit extension of the link should the feeder house be raised above a position necessary to affect the closing of the trap door.