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

if it ain’t broke, don’t fix it

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

   I know it’s an ugly-looking antenna, but you know what they say: If it ain’t broke, don’t fix it.

• leave well enough alone
• never change a running system

• don’t change a winning team
• don’t change horses in midstream