diff --git a/tests/validation/run_refined_dfg.py b/tests/validation/run_refined_dfg.py
index 3e0eeb7..5038f84 100644
--- a/tests/validation/run_refined_dfg.py
+++ b/tests/validation/run_refined_dfg.py
@@ -270,10 +270,14 @@ def host_geometry(source, h, collision="SRT", jet_scenario="none", placement="wi
     pair = FixedPatch2D.from_config(cfg, PLACEMENTS[placement])
     layout = BlockLayout2D.build(cfg.ny, cfg.nx, *BASE_BLOCK)
     validate_channel_config(cfg, [BASE_BLOCK, FINE_BLOCK])
-    # Historical pinned source (jet_scenario none) names it blocked_base_tables;
-    # the current checkout (public Jet scenarios) names it blocked_coarse_tables.
-    coarse_tables = (refinement_tables.blocked_base_tables if jet_scenario == "none"
-                     else refinement_tables.blocked_coarse_tables)
+    # Select by the imported source's own API, not by scenario: the pinned historical
+    # source (verify_source) defines blocked_base_tables, the current checkout (host
+    # tests, public Jet scenarios) blocked_coarse_tables. Exactly one must exist.
+    names = [n for n in ("blocked_base_tables", "blocked_coarse_tables")
+             if hasattr(refinement_tables, n)]
+    if len(names) != 1:
+        raise RuntimeError(f"Unexpected coarse transfer table API: {names}")
+    coarse_tables = getattr(refinement_tables, names[0])
     targets = coarse_tables(pair, layout, np.argsort(pair.coalesce_coarse))[1]
     validate_channel_transfers(pair, layout, targets)
     BlockLayout2D.build(*pair.fine_shape, *FINE_BLOCK, periodic=(False, False))