The rapid adoption of robots in workplaces has raised concerns among employees who view the robots as a potential threat to their job security. This study therefore aims to provide valuable insights into this psychologically and managerially important issue from a design perspective. In particular, this study examines how to alleviate employees' concerns about job insecurity resulting from the adoption of robots. Across seven studies with different samples, we showed that the humanlike features of robots in the workplace increase employees' perceived job insecurity, because these features increase their engagement in social comparison with robots. This research contributes to the literature on job insecurity, robot anthropomorphism, and social comparison. Moreover, this research provides important managerial implications for the design of robots in the workplace in light of employees' job insecurity as a result of robots in the workplace.