diff --git a/account.py b/account.py
index 0c17695c4f..54910e4c7a 100644
--- a/account.py
+++ b/account.py
@@ -854,6 +854,7 @@ class Account(ModelSQL, ModelView):
             default = {}
         default['left'] = 0
         default['right'] = 0
+        default.setdefault('deferrals', [])
         res = super(Account, self).copy(ids, default=default)
         self._rebuild_tree('parent', False, 0)
         return res