This study investigated the effect of first language (L1) on the reading of modifier–head case agreement in second language (L2) Finnish by native Russian and Chinese speakers. Russian is similar to Finnish in that both languages use case endings to mark grammatical roles, whereas such markings are absent in Chinese. The critical nouns were embedded in sentences, where the head noun was either preceded by an agreeing modifier or the modifier was absent. Readers’ eye fixation patterns were used as indices of online processing. Both natives and non-natives showed a facilitatory effect of agreement; reading head nouns was easier when they were preceded by an agreeing modifier. Typological distance in terms of the structural complexity of words between L1 and L2 did not influence the processing.