Firm corruption has become an institutionalized practice in Africa. We show that this phenomenon can be partly explained by the slave trade history, which was corrupt in its own right. Combining historical data of the slave trade with contemporary firm-level survey data on firm corruption, we find a robust, positive relationship between the number of slaves exported from a country and current firm corruption intensity and depth. In areas that suffered high historical levels of slave extraction, modern-day firms pay more bribes. To explore the persistence of structural corruption, we draw on Rawls’s theory of justice and Jean-Paul Sartre’s account of bad faith to argue that injustice is one of the specific features that characterize extractive institutions conducive to corruption. By employing the World Values Survey (WVS), we examine the injustice of formal institutions and informal norms as potential channels to explain the historical slave trade’s impact on present-day firm corruption. Our study contributes to the institutional theory and firm corruption literature by showing that the taken-for-granted business practice of firm corruption in Africa has roots of injustice that run deeply into the slave trade history.