In a recent book (_Lying and insincerity_, Oxford University Press, 2018), Andreas Stokke argues that one lies iff one says something one believes to be false, thereby proposing that it becomes common ground. This paper shows that Stokke’s proposal is unable to draw the right distinctions about insincere performative utterances. The objection also has repercussions on theories of assertion, because it poses a novel challenge to any attempt to define assertion as a proposal to update the common ground.