The RPython framework’s meta-tracing JIT compiler uses a single generic tracer for all interpreters written in the RPython language, but this genericity causes overhead: the tracer dispatches every operation through an opcode lookup and performs redundant bookkeeping even for pure operations. We propose GenExtension, which specializes the tracer to a given interpreter at translation time, eliminating dynamic dispatch and skipping recording and heap-cache invalidation for pure operations. We implemented a prototype in RPython and applied it to the PyPy interpreter. On 28 benchmarks from the PyPy benchmark suite, GenExtension reduces tracing time by 11% (geometric mean) and resume data generation (the metadata needed to deoptimize back to the interpreter) by 28%, while producing nearly equivalent machine code and leaving total execution time unchanged (0.99×). Extending the specialization to more operation classes to reduce total execution time is future work.