The intramedullary nail has a longitudinal axis, a proximal end, a distal end, at least one hole that extends transversely to the longitudinal axis and is situated in a plane with a defined diameter to accommodate a locking element, as well as a longitudinal slot extending in the plane parallel to the longitudinal axis. In the unexpanded state of the intramedullary nail the longitudinal slot has a width b, measured perpendicularly to the plane in the region outside of the holes, said slot being maximum 0.6 times that of the smallest defined diameter of the holes.