Many countries have become increasingly aggressive in their efforts to stop unauthorized migration, but most evidence suggests that immigration enforcement policies do not effectively deter migrants. We draw on literature from social psychology, specifically the dual-system model of decision-making, which differentiates between judgments that are subject to considerations of risks and costs and judgments that are ‘non-consequentialist’. Non-consequentialist decision-making is founded in moral intuition and rejects rational considerations of costs and benefits. This mental process would render the deterrence tools of the state powerless. We posit that some, but not all, forms of unauthorized migration will invoke non-consequentialist decision-making. When considering semi-legal strategies, which individuals may perceive as ‘bending the law’ rather than breaking it, aspiring migrants are likely to weigh the risks and costs of enforcement policies. Meanwhile, when considering fully illegal migration strategies, aspiring migrants will prioritize moral considerations for breaking the law rather than the consequences of breaking the law. We find evidence for our theory using original population-based list experiments along with focus groups with aspiring migrants in an origin country.