The present invention relates to a jet engine nacelle comprising a forward air inlet section, a mid-section intended to surround a jet engine fan, and an aft section equipped with at least one thrust reversal system comprising, on the one hand, means for deflecting at least part of an air flow of the jet engine and, on the other hand, at least one cowl (12) mounted translatably along at least one guide rail (15) in a direction substantially parallel to a longitudinal axis of the nacelle, said movable cowl being able to switch alternately from a closed position, in which it provides the nacelle with aerodynamic continuity and covers the deflection means, to an open position in which it opens a passage in the nacelle and uncovers said deflection means, the nacelle being characterized in that the aft section is equipped with at least one stud (18) mounted such that it can move over a fixed structure of the aft section in the region of the guide rail between a retracted position, in which said stud is withdrawn from the running track of the rail and allows a translational movement of the movable cowl, and an engaged position, in which it forms a stop capable of preventing the movable cowl from sliding in the downstream direction of the nacelle.