Prosthesis (1) comprising one porous mesh (2) comprising a first face and a second face opposite the first face, the prosthesis (1) comprising: —one porous strengthening means (6) which strengthens the mesh (2) and is intended to cover at least part of one of said first and second faces of the mesh (2), —fastening means for fastening the strengthening means (3) to the mesh (2), in a position fastened to the mesh (2), the strengthening means (6) covers a peripheral part (7) of one of said first and second faces of the mesh.