Do cross-lingual interactions occur even with structures of different word order in different languages of bilinguals? Or could the latter provide immunity to interference of the contrasting characteristics of the other language? To answer this question, we examined the reported speech production (utterances reporting what just happened; e.g., Holly asked what Eric ate) of two groups of proficient, unbalanced bilinguals with varying similarity between their native (L1-Spanish/L1-Dutch) and second language (L2-English). The results showed that both groups of bilinguals produced word order errors when formulating indirect What-questions in L2, regardless of how similar the L1 was to the L2 in that respect. Our findings suggest that in the case of reported speech production in the examined bilingual groups, cross-linguistic syntactic differences by themselves suffice to induce language interference, and that the degree of similarity between the L1 and the L2 does not seem to modulate the magnitude of this effect.