diff --git a/product/ERP5SyncML/Subscription.py b/product/ERP5SyncML/Subscription.py
index 64e1e1d78a8f0b25b1b441ba37cbe709adb864c1..7b768a2efdaf387e530538ab1c435ffcbc17f88c 100644
--- a/product/ERP5SyncML/Subscription.py
+++ b/product/ERP5SyncML/Subscription.py
@@ -1060,7 +1060,7 @@ class Subscription(Folder, SyncCode):
     """
     if signature.getGid() in self.objectIds():
       self._delObject(signature.getGid())
-    self._setObject( signature.getGid(), signature )
+    self._setObject( signature.getGid(), aq_base(signature) )
 
   def delSignature(self, gid):
     """