diff --git a/product/ERP5/Document/SimulationMovement.py b/product/ERP5/Document/SimulationMovement.py
index ddefe08d1da4ce20d43b8146a1de5d09f0cea8f4..c9f941e5b0c68a7394f9761f04e32cd04e6febbd 100644
--- a/product/ERP5/Document/SimulationMovement.py
+++ b/product/ERP5/Document/SimulationMovement.py
@@ -36,6 +36,8 @@ from Products.ERP5.Document.Movement import Movement
 
 from zLOG import LOG
 
+from Acquisition import aq_base
+
 # XXX Do we need to create groups ? (ie. confirm group include confirmed, getting_ready and ready
 
 parent_to_movement_simulation_state = {
@@ -131,7 +133,7 @@ class SimulationMovement(Movement):
     """
       Returns the current state in causality
     """
-    return getattr(self, 'causality_state', 'solved')
+    return getattr(aq_base(self), 'causality_state', 'solved')
 
   security.declareProtected( Permissions.ModifyPortalContent,
                              'setCausalityState')