close the stable door after the horse has bolted

close the stable door after the horse has bolted

To try to prevent or rectify a problem after the damage has already been done. It isn't worth replacing the oil filter on the engine now—you can't close the stable door after the horse has bolted.
See also: after, bolt, close, door, horse, stable
References in periodicals archive ?
And, in a close the stable door after the horse has bolted operation, the government attempted to sue Mittal in the High Court to recover the clean-up costs.