We report the results from two experiments examining native and non-native German speakers' sensitivity to crossover constraints on pronoun resolution. Our critical stimuli sentences contained personal pronouns in either strong (SCO) or weak crossover (WCO) configurations. Using eye-movement monitoring during reading and a gender-mismatch paradigm, Experiment 1 investigated whether a fronted "wh"-phrase would be considered as a potential antecedent for a pronoun intervening between the "wh"-phrase and its canonical position. Both native and non-native readers initially attempted coreference in WCO but not in SCO configurations, as evidenced by early gender-mismatch effects in our WCO conditions. Experiment 2 was an offline antecedent judgement task whose results mirrored the SCO/WCO asymmetry observed in our reading-time data. Taken together, our results show that the SCO constraint immediately restricts pronoun interpretation in both native and non-native comprehension, and further suggest that SCO and WCO constraints derive from different sources.