According to one influential response to evolutionary debunking arguments against moral realism, debunking arguments fail to undermine our moral beliefs because they fail to imply that those beliefs are insensitive or unsafe. The position that information about the explanatory history of our belief must imply that our beliefs are insensitive or unsafe in order to undermine those beliefs has been dubbed “Modal Security”, and I therefore label this style of response to debunking arguments the “modal security response”. An alternative position, (...) that our beliefs can be defeated if we accept those beliefs are not explained by the relevant facts, I call “explanationism”. In this article, I argue against Modal Security in favour of explanationism. First, I present two examples from the literature that appear to support explanationism, and I argue that these examples imply that the modal security response is fundamentally misguided about the nature of epistemic defeat. I then consider a recent response from Justin Clarke-Doane and Dan Baras, who claim that examples of this kind fail because they are either incoherent or involve a failure of modal security. I argue that, due to their position on the failure of evolutionary debunking arguments, Clarke Doane and Dan Baras are committed to the existence of coherent, sufficiently simple examples that can help us arbitrate between explanationism and modal security. I then construct such an example and argue that it clearly indicates that we should reject Modal Security in favour of explanationism. This implies the modal security response to debunking arguments fails. (shrink)