diff --git a/runs/frontier-fidelity-envelope-v1/run_frontier_qwen235_v020_surface.py b/runs/frontier-fidelity-envelope-v1/run_frontier_qwen235_v020_surface.py
index 2f25871..3ec8eb5 100644
--- a/runs/frontier-fidelity-envelope-v1/run_frontier_qwen235_v020_surface.py
+++ b/runs/frontier-fidelity-envelope-v1/run_frontier_qwen235_v020_surface.py
@@ -112,6 +112,7 @@ def knobs(config: Config, paths: dict[str, Path], contract: dict, cache: Path, p
         "batch_size_cap": config.mns,
         "max_tokens_in_batch": 8192,
         "long_prefill_token_threshold": 0,
+        "enable_chunked_prefill": True,
         "block_size": 16,
         "num_blocks_mode": "explicit",
         "num_blocks": int(resolved["num_gpu_blocks"]),