diff --git a/tools/battery/still_battery.py b/tools/battery/still_battery.py
index 67276774b..57bb93a0b 100644
--- a/tools/battery/still_battery.py
+++ b/tools/battery/still_battery.py
@@ -217,6 +217,9 @@ def refine(wd, e, cache):
     if free is None:
         return None, None, "no free set in the deposition"
     env = model_check.ccp4_env()
+    if xyz.endswith(".cif"):  # dimple takes PDB-format coordinates only
+        subprocess.run(["gemmi", "convert", xyz, "deposited.pdb"], cwd=wd, env=env, capture_output=True)
+        xyz = os.path.join(wd, "deposited.pdb")
     subprocess.run(["reindex", "hklin", "p.mtz", "hklout", "p_sg.mtz"], cwd=wd, env=env,
                    input=f"SYMM '{e['sg']}'\nEND\n", capture_output=True, text=True)
     with open(os.path.join(wd, "dimple.out"), "w") as log: