An assembly for an aircraft, which includes a pylon with a bearing face and a contact face, an engine mount with a bearing face and a contact face bearing against the contact face of the pylon, at least two bolts comprising a threaded stem with a head and a nut bearing against the bearing face of the engine mount, for each head, a bearing washer with a first bearing face and a second bearing face, where the second bearing face of the bearing washer bears against the bearing face of the pylon, and where the head bears against the first bearing face of the bearing washer, a shoe, and, for each bearing washer, a clamp that is secured to the shoe and comprises a first branch and a second branch between which the bearing washer is clamped and is free to rotate.