if it ain't broke, don't fix it

• if it ain't broken, don't fix it

Attested since c. 1962,^[1] originally Southern United States English; popularized by T. Bert Lance in May 1977.^[2]

if it ain't broke, don't fix it

1. It is wise to leave something alone and to avoid attempting to correct, fix, or improve what is already sufficient (often with an implication that is the attempted improvement is risky and might backfire).

   I know it’s an ugly-looking antenna, but it gets the job done, and if it ain't broke, don't fix it.

• don't mess with success
• if it ain't busted, don't fix it
• leave well enough alone
• if it works, it works
• perfect is the enemy of good
• better is the enemy of good

• don’t change a winning team
• don’t change horses in midstream
• don’t mess with success
• let sleeping dogs lie