Inspired by the emerging literature on unintended consequences of EU external action, this article studies how the anticipation of negative unintended consequences factors into EU policy-making. Using policy learning analytical lens, case study research strategy and process-tracing method, this article examines EU policy-making on conflict minerals: when respective EU policy was drafted, the negative unintended consequences of the earlier US conflict minerals legislation figured prominently in the debate. The analysis shows why and how major differences between US and EU conflict minerals legislation have resulted from bounded lessons-drawing driven by two opposing transatlantic advocacy coalitions. Eventually, the EU designed its conflict minerals policy so as to mitigate perceived negative unintended consequences of the earlier US law. The article contributes to literatures on unintended consequences of EU external action, policy learning and specifically bounded lessons-drawing in EU context, and conflict minerals legislation.