Increasing heterogeneity of participants that form the basis of WTO trade negotiations has raised concerns about unfair treatment of weak countries due to their lack of bargaining power. The WTO responds to these concerns by arguing that the institutional design with its specific rules such as the principle of reciprocity serves to reduce inequalities in bargaining power by giving smaller (weaker) countries more voice. A recent study has challenged this result for a particular type of reciprocity, namely the volume approach. Given the wide discretion of how reciprocal concessions are conducted, I give a more complete picture of how different kinds of reciprocity affect the bargaining outcome of asymmetric countries. It turns out that, while the volume approach amplifies the negative effects of power asymmetries, a tariff formula approach has the ability to reverse this effect. For low symmetries, the Swiss formula does the best job, whereas for larger power differences, a linear formula is best suited to reduce the impact of power asymmetries.