This paper adds to the debate over whether self-policing can increase environmental protection by considering an issue that has been ignored in previous models-that self-policing may influence future enforcement. The model combines self-policing with targeted enforcement and allows for both deliberate and inadvertent violations. As expected, rewarding self-policers with more lenient future enforcement increases auditing, remediation, and disclosure of inadvertent violations. Self-policing can also serve as a complement to deliberate compliance and can thus further increase environmental performance. However, under reasonable conditions, self-policing can be a substitute for deliberate compliance and could therefore be detrimental to environmental protection.