zéi​qù​guān​mén

to lock the door after the thief has left

贼去关门 賊去關門 zéi​qù​guān​mén
to lock the door after the thief has left
To take precautions only after a disaster or loss has already occurred; similar to the English idiom "to lock the stable door after the horse has bolted".

Cross-References

Synonym

Variant of