Var.: Берегись бед, пока их нет Cf:
A danger foreseen is half avoided (Am., Br.). An ounce of prevention is worth a pound of cure (Am.). Prevention is better than cure (Am., Br.). Study sickness while you are well (Br.)
Русско-английский словарь пословиц и поговорок. Академик.ру. 2013.