straighten up (one's) act

Translations
взяться за ум
He needs to straighten up his act if he wants to keep his job.
Ему нужно взяться за ум, если он хочет сохранить свою работу.
Definitions
To improve one's behavior or performance, often by becoming more responsible, disciplined, or law-abiding after a period of misconduct or carelessness.
Words
act

noun
акт
straighten

verb
выпрямлять
straighten up

verb
выпрямиться