The ability of political systems to adopt policy reforms contributes to their internal stability. This article analyses 29 anti-corruption reforms in seven sub-Saharan countries. It seeks to explain the level of adopted reform in these countries from conflicts of interests between policy actors. Two groups of policy actors are distinguished: veto-players (endowed with an exercisable veto) and stakeholders (with an interest in policy reforms). A veto-player model is applied and extended with effects of (a) policy polarization between all policy actors and (b) institutional fractionalization between veto-players and stakeholders. The authors hypothesize a negative (interaction) effect of these variables with the win-set on the level of reform. As expected, the core variable of the veto-player model, size of the win-set of the status quo, significantly and positively affects the level of adopted reform. Unexpectedly, the number of veto-players has a significant and positive effect on the level of reform, whereas polarization among veto-players does not affect the level of reform. In contrast, fractionalization between veto-players and stakeholders has a significant negative direct effect on the level of anti-corruption reform and a weak interaction effect with size of the win-set. Thus, even when veto-players agree on the desirability of anticorruption reforms, the adoption of reforms is obstructed by a high level of fractionalization between veto-players and stakeholders.