A central question in the second language (L2) processing literature has been whether and under what conditions readers reactivate copies of syntactic movement operations at structurally defined gap sites. The present study contributes to the debate by examining the role of similarity-based interference in processing intermediate copies in long-distance dependencies with either three similar description noun phrases (NPs) (the nurse, the doctor, the patient) or two similar (the nurse, the doctor) and one dissimilar NP (John). Sixty-nine advanced L2 readers of English with either French (+ wh-movement) or Persian (− wh-movement) as their L1 and 33 native English readers (+ wh-movement) participated in a self-paced reading task involving long-distance dependencies. The results indicate that L2 readers process wh-dependencies in the same way as native readers, both in structures with similar and dissimilar NPs. This suggests that highly advanced L2 readers reactivate moved elements at inter-causal boundaries and process long-distance wh-dependencies in the same way as native readers, especially when the NPs involved in a dependency relation are sufficiently distinguishable.