We analyze the effect of investments in corporate social responsibility (CSR) on workers’ motivation. In our experiment, a gift exchange game variant, CSR is captured by donating a certain share of a firm’s profit to a charity. We are testing for CSR effects by varying the possible share of profits given away. Additionally, we investigate the effect of a mission match, i.e., a worker preferring the same charity the firm is actually donating to. Our results show that on average workers reciprocate investments into CSR with increased effort. A mission match does result in higher effort, but only when investment into CSR is high.