Here, we present a module to introduce student peer review of laboratory reports to engineering students. Our findings show that students were positive and felt that they had learnt quite a lot from this experience. The most important part of the module was the classification scheme. The scheme was constructed to mimic the way an expert would argue when making a fair judgement of a laboratory report. Hence, our results may suggest that the success of the module design comes from actively engaging students in work that is more related to 'arguing like an expert' than to only supply feedback to peers, which in such a case would implicate a somewhat new direction for feedback research. For practitioners, our study suggests that important issues to consider in the design are (i) a clear and understandable evaluation framework, (ii) anonymity in the peer-review process and (iii) a small external motivation.