It is generally acknowledged that testifiers can play a central role in the production of knowledge and other valuable epistemic states in others. But does such a role warrant any form of epistemic credit and is an agent more successful qua epistemic agent insofar as she is a successful testifier? I here propose an affirmative answer to both questions. The core of the current paper consists in a sustained defence of this proposal against a series of objections. I further argue (...) that the proposal allows us to recognize an important additional epistemic harm that arises in cases of testimonial injustice beyond those described by Miranda Fricker. Finally, I conclude by distinguishing between four kinds of credit - distinctions that allow us to avoid inappropriately attributing epistemic credit in problematic cases. If the current proposal is correct, our understanding of successful epistemic agents needs to be significantly modified in order to take into account their role in producing epistemically valuable states in others. (shrink)