Using a randomised experiment with an automobile manufacturing firm in China, we measure the effects of letting workers evaluate their managers on worker and firm outcomes. In the treatment teams, workers evaluate their supervisors monthly. We find that providing feedback leads to significant reductions in worker turnover and increases in team-level productivity. In addition, workers report higher levels of happiness and positive mood. The evidence suggests that these results are driven by changes in the behavior of managers and an overall better relationship between managers and workers.