Necessitarian accounts of the laws of nature meet an apparent difficulty: for them, counterlegal conditionals, despite appearing to be substantive, seem to come out as vacuous. I argue that the necessitarian may use the presuppositions of counterlegal discourse to explain this. If the typical presupposition that necessitarianism is false is made explicit in counterlegal utterances, we obtain sentences such as ‘If it turns out that the laws of nature are contingent, then if the laws had been otherwise, then such and such would have been the case’, which are non-vacuous and very often true. This goes a long way towards resolving the difficulty for necessitarianism.