The scholarship on the Modern German periphrastic future, or the werden future (that is, werden + infinitive) has brought forth different hypotheses about its origins. One of these hypotheses states that it developed from werden + present participle in the 13th century (for example, Bech 1901). While many have criticized this hypothesis, no one until now has proposed a valid solution for the problem. In this study, I carried out a comprehensive examination of the instances of werden in combination with present participles and infinitives in Middle and Early New High German. The analysis indicates that although werden + present participle and werden + infinitive were often used in similar contexts, the former construction was not the source from which the werden future emerged. Old High German data also show the use of werden + infinitive, which suggests that it was already well established in the first two centuries of the Middle High German period. This provides evidence against the view that the construction developed as late as the 13th century. I also address the grammaticalization process that werden + infinitive underwent during the Early New High German period and suggest that it culminated in the 16th century.