diff --git a/library/cadbiom/models/clause_constraints/mcl/CLUnfolder.py b/library/cadbiom/models/clause_constraints/mcl/CLUnfolder.py
index 08e1c132a32a5fa005ca8744c7deee8ee96ca114..d91f1f264d6e6f8d14d369de2053bc3270810c61 100644
--- a/library/cadbiom/models/clause_constraints/mcl/CLUnfolder.py
+++ b/library/cadbiom/models/clause_constraints/mcl/CLUnfolder.py
@@ -1112,8 +1112,7 @@ class CLUnfolder(object):
 
         if self.__dimacs_invariant:
             # Add DIMACS aux clauses initial properties
-            ## TODO: pas de append ? tester avec... => aucun changement, pas de test unitaire ici...
-            self.__invariant_constraints += self.__dimacs_invariant
+            self.__invariant_constraints.append(self.__dimacs_invariant)
 
     def __init_variant_constraints_0(self):
         """Code variant constraints in a numerical clause.