close the stable door after the horse has bolted

US /kloʊz ðə ˈsteɪbl dɔːr ˈæftər ðə hɔːrs hæz ˈboʊltɪd/
UK /kloʊz ðə ˈsteɪbl dɔːr ˈæftər ðə hɔːrs hæz ˈboʊltɪd/
"close the stable door after the horse has bolted" picture
1.

zamykać drzwi stajni po ucieczce konia, musztarda po obiedzie

to take precautions after a misfortune has already happened

:
Trying to fix the security breach now is like closing the stable door after the horse has bolted.
Próba naprawienia naruszenia bezpieczeństwa teraz jest jak zamykanie drzwi stajni po ucieczce konia.
They should have implemented stricter rules earlier, but it's too late now; they're just closing the stable door after the horse has bolted.
Powinni byli wprowadzić surowsze zasady wcześniej, ale teraz jest za późno; po prostu zamykają drzwi stajni po ucieczce konia.