While Dutch welke 'which'-questions are structurally ambiguous, number agreement cues can disambiguate them. Despite such agreement cues, children misinterpret object questions as subject questions (Metz et al. 2010(Metz et al. , 2012Schouwenaars et al. 2014). We investigated if adding another cue, specifically, topicality in a discourse context, helps the interpretation of which-questions in two groups of Dutch children (5;5, n = 15 and 8;5, n = 21). Using a referent-selection task, we manipulated number on the verb and postverbal NP to create unambiguous wh-questions. Moreover, the questions were preceded by a discourse which established a topic, relating either to the wh-referent or the postverbal NP referent. Nevertheless, both 5-and 8-year-olds misinterpreted object questions as subject questions, ignoring the number and topicality cues to resolve the (local) ambiguity of which-questions. Our results confirm the effect of a subject-first bias in children's interpretation of wh-questions. We conclude that topicality, in combination with number agreement, is not strong enough to overrule this subject-first bias.