This contribution explores the historical development of modal verbs in Dutch. As opposed to their English counterparts, modals in present-day Dutch may be non-finite, and may appear under other auxiliaries in long verb clusters. This was not the case in Old Germanic languages. The first Dutch attestations of modal infinitives are in the complement of zullen, a verb which was undergoing a semanticchange from modality to futurity/irrealis. This [zullen + modal infinitive + main verb] construction was probably a Middle Dutch innovation, which most likely had its origin in southern Dutch dialects. From there, it gradually spread to other dialects in the course of the Early Modern Dutch period. The paper discusses the possible relationship between this syntactic innovation and the semantic changes that Dutch modal verbs underwent in the same period.