In an ambitious public sector reform experiment, the Ghana government doubled its police officer salaries in 2010 in part to mitigate petty corruption on its roads, while leaving salaries for other officials unchanged. Using unique data on bribes paid from truck trips in West Africa, we evaluate impacts of higher police salaries on petty corruption using a difference-in-difference method. Rather than decrease petty corruption, the salary policy significantly increased the police efforts to collect bribes, the value of bribes and the amounts given by truck drivers to policemen in total. The higher results are stable across alternative specifications.