A high lift system for an aircraft includes a basic body, a flap which is movably mounted on the basic body and has a flap edge, and a retaining element. The high lift system is set up to form a gap between the flap edge and the basic body. The retaining element is mounted on a region of the flap close to the flap edge and extends towards the basic body to restrict the distance between the flap edge and the basic body. The retaining element is preferably configured as a linear attachment means. Consequently, a gap dimension between a flap and a basic body can be influenced to restrict flexing effects during loading of the flap and of the basic body.