The Molinist doctrine that God has middle knowledge requires that God knows the truth-values of counterfactuals of freedom, propositions about what free agents would do in hypothetical circumstances. A well-known objection to middle knowledge, the grounding objection, contends that counterfactuals of freedom have no truth-value because there is no fact to the matter as to what an agent with libertarian freedom would do in counterfactual circumstances. Molinists, however, have offered responses to the grounding objection that they believe are adequate for maintaining the coherence of middle knowledge. I argue that these responses to the grounding objection are not adequate, and that what I call the ‘generic grounding objection’ still poses a serious challenge to middle knowledge.