diff --git a/bt5/erp5_simulation_legacy/DocumentTemplateItem/SimulationLegacyPatches.py b/bt5/erp5_simulation_legacy/DocumentTemplateItem/SimulationLegacyPatches.py
index 18ba2d4d591b638932cb15c65b631c8a28285eea..1b283c6a32a95b8aaae07730169d5a2361d62e4e 100644
--- a/bt5/erp5_simulation_legacy/DocumentTemplateItem/SimulationLegacyPatches.py
+++ b/bt5/erp5_simulation_legacy/DocumentTemplateItem/SimulationLegacyPatches.py
@@ -73,7 +73,10 @@ def patch():
   ## SimulationMovement
 
   from Products.ERP5.Document.SimulationMovement import SimulationMovement
-  del SimulationMovement.isFrozen
+  try:
+    del SimulationMovement.isFrozen
+  except AttributeError:
+    pass
 
   def isCompleted(self):
     """Zope publisher docstring. Documentation in ISimulationMovement"""
diff --git a/bt5/erp5_simulation_legacy/bt/revision b/bt5/erp5_simulation_legacy/bt/revision
index 301160a93062df23030a69f4b5e4d9bf71866ee9..f11c82a4cb6cc2e8f3bdf52b5cdeaad4d5bb214e 100644
--- a/bt5/erp5_simulation_legacy/bt/revision
+++ b/bt5/erp5_simulation_legacy/bt/revision
@@ -1 +1 @@
-8
\ No newline at end of file
+9
\ No newline at end of file