Previous evidence suggests that grammatical constraints have a rapid influence during language comprehension, particularly at the level of word categories (noun, verb, preposition). These findings are in conflict with a recent study from Angele, Laishley, Rayner, and Liversedge (2014), in which sentential fit had no early influence on word skipping rates during reading. In the present study, we used a gaze-contingent boundary change paradigm to manipulate the syntactic congruity of an upcoming noun or verb outside of participants' awareness. Across 3 experiments (total N = 148), we observed higher skipping rates for syntactically valid previews ("The admiral would not confess" . . .), when compared with violation previews ("The admiral would not surgeon" . . .). Readers were less likely to skip an ungrammatical continuation, even when that word was repeated within the same sentence ("The admiral would not admiral" . . .), suggesting that word-class constraints can take precedence over lexical repetition effects. To our knowledge, these results provide the first evidence for an influence of syntactic context during parafoveal word recognition. On the basis of the early time-course of this effect, we argue that readers can use grammatical constraints to generate syntactic expectations for upcoming words.