A timepiece regulating mechanism including an escape wheel set subjected to a drive torque, and at least one resonator including a rigid structure connected to a plate by an elastic return and carrying at least one inertia arm cooperating with this escape wheel set via magnetically and/or electrically charged tracks comprised both in this inertia arm and in this escape wheel set, to form a synchronizing device between the escape wheel set and the resonator, and the synchronizing device is protected from loss of synchronization in the event of an accidental torque increase by a mechanical anti-desynchronization mechanism including mechanical escapement stops carried by the escape wheel set, and at least one mechanical inertia arm stop, carried by the inertia arm, and together arranged to maintain stopped in abutment in such event.