A timepiece with a mechanical movement which includes an indicator mechanism of at least one time data item, a mechanical resonator forming a mechanical oscillator which paces the running of the indicator mechanism, and a regulation device to prevent a potential time drift in the running of the indicator mechanism. The regulation device is formed by a master oscillator and a mechanical braking device of the mechanical resonator, this mechanical braking device being arranged to be able to apply periodically to the mechanical resonator braking pulses at a braking frequency determined by the master oscillator. The system, formed of the mechanical resonator and the mechanical braking device, is configured so as to enable the mechanical braking device to be able to start the braking pulses at any position of the mechanical resonator. The braking pulses have a duration less than one quarter of a set-point period.