diff --git a/src/pyhpp/manipulation/constraint_graph_factory.py b/src/pyhpp/manipulation/constraint_graph_factory.py
index 9b9af2b..f9c3759 100644
--- a/src/pyhpp/manipulation/constraint_graph_factory.py
+++ b/src/pyhpp/manipulation/constraint_graph_factory.py
@@ -905,7 +905,7 @@ def __init__(self, graph, constraints=None):
         self.edge_objects = {}
         self.preplaceDistance = {}
         # Store loop transition by state
-        self.loopTransition = dict()
+        self.loopTransition = {}
 
     # # \name Default functions
     # \{