An aircraft engine attachment connecting an attachment body and a primary structure of an aircraft pylon, the engine attachment comprising a shear pin immobilized in translation by a first immobilization system that comprises a shoulder and a removable stop that are integral with the primary structure, between which a flange of the shear pin is immobilized, and a second immobilization system that comprises, first, a groove positioned in an extension of the shear pin and, second, a fork connected to the primary structure via at least one removable link and interacting during operation with the groove in such a manner as to immobilize the shear pin in translation.