A turbojet engine nacelle includes a fixed structure, which has a fan casing of the turbojet engine and a front frame mounted downstream of the fan casing and directly or indirectly supporting cascade vanes. The front frame is able to collaborate with a thrust reverser cowling sliding between a closed position covering the flow-diverting means and an open position exposing this flow-diverting means. At least one reinforcing structure of the engine nacelle transmits load between the fan casing and the front frame. The reinforcing structure extends along the longitudinal axis of the nacelle and supports a third line of defense and/or an inhibiting device between the front frame and the thrust reverser cowling.