diff --git a/src/pymatgen/transformations/site_transformations.py b/src/pymatgen/transformations/site_transformations.py
index 220769fd0f4..f5a331e44ac 100644
--- a/src/pymatgen/transformations/site_transformations.py
+++ b/src/pymatgen/transformations/site_transformations.py
@@ -316,7 +316,7 @@ def _complete_ordering(self, structure: Structure, num_remove_dict):
             for ii, t_sites in enumerate(tested_sites):
                 t_energy = all_structures[ii]["energy"]
                 if abs((energy - t_energy) / len(s_new)) < 1e-5 and sg.are_symmetrically_equivalent(
-                    sites_to_remove, t_sites, symm_prec=symprec
+                    set(sites_to_remove), set(t_sites), symm_prec=symprec
                 ):
                     already_tested = True