This paper studies the role of financial incentives in breaking harmful norms within organization. Beyond monetary gains, visible incentives can provide a credible justification for taking actions otherwise costly vis-à-vis peers. I test this hypothesis on a high-stakes and widespread harmful behavior: overspeeding. Multiple experiments with 360 motortaxi groups in Uganda show that: (i) drivers' demand for no-speeding incentives increases when incentives have social justification properties, (ii) the availability of these properties doubles the effectiveness of the contract, increasing speed limit compliance by 45 percent, and (iii) labor supply is not affected, while disposable income increases because of a reduction in marginal costs. My findings highlight how public disclosure of financial incentives can drive the reduction of harmful behaviors that are otherwise perpetuated by social pressures within organizations.