An antitheft device for the steering column of a vehicle

An antitheft device for the steering column of a vehicle, comprising: - a blocking part (6) comprising a bolt (8) for blocking the steering column, and a control member (22) capable of controlling blocking in position of the bolt; and - an access part (4) comprising a cam (30) cooperating with the bolt (8); wherein the cam (30) comprises at the periphery at least a cavity (32) disposed for receiving the control member (22) when the latter is deformed.