Contextualists such as Cohen and DeRose claim that the truth conditions of knowledge attributions vary contextually, in particular that the strength of epistemic position required for one to be truly ascribed knowledge depends on features of the attributor's context. Contextualists support their view by appeal to our intuitions about when it's correct (or incorrect) to ascribe knowledge. Someone might argue that some of these intuitions merely reflect when it is conversationally appropriate to ascribe knowledge, not when knowledge is truly ascribed, and so try to accommodate these intuitions even on an invariantist view. DeRose (Blackwell Guide to Epistemology, 1998; Philosophical Review, 2002) argues that any such 'warranted assertibility manoeuvre', or 'WAM', against contextualism is unlikely to succeed. Here, I argue that his objections to a WAM against contextualism are not persuasive and offer a pragmatic account of the data about ascriptions of knowledge.