Leaders who express an ethical identity are proposed to affect followers' attitudes and work behaviors. In two multi-source studies, we first test a model suggesting that work engagement acts as a mediator in the relationships between ethical leadership and employee initiative (a form of organizational citizenship behavior) as well as counterproductive work behavior. Next, we focus on whether ethical leadership always forms an authentic expression of an ethical identity, thus in the second study, we add leader Machiavellianism to the model. For Machiavellian leaders, the publicly expressed identity of ethical leadership is inconsistent with the privately held unethical Machiavellian norms. Literature on surface acting suggests people can at least to some extent pick up on such inauthentic displays, making the effects less strong. We thus argue that the positive effects of ethical leader behavior are likely to be suppressed when leaders are highly Machiavellian. Support for this moderated mediation model was found: The effects of ethical leader behavior on engagement are less strong when ethical leaders are high as opposed to low on Machiavellianism.