diff --git a/src/dmt_api_repository_migration.erl b/src/dmt_api_repository_migration.erl
index f85dc39..15c15a0 100644
--- a/src/dmt_api_repository_migration.erl
+++ b/src/dmt_api_repository_migration.erl
@@ -28,6 +28,10 @@ migrate_legacy_payment_system_conditions(Data) ->
     %    anyway.
     genlib_ted:run(
         fun
+            ({AllAnyOf, PredicateSet}, _Annos) when AllAnyOf == all_of; AllAnyOf == any_of ->
+                % NOTE
+                % Reconstruct potentially broken set (e.g. with duplicate elements).
+                {replace, ordsets:from_list(migrate_legacy_payment_system_conditions(PredicateSet))};
             (Condition = #domain_BankCardCondition{}, _Annos) ->
                 {replace, migrate_legacy_payment_system_condition(Condition)};
             (_, _Annos) ->