diff --git a/addons/account/models/account_move.py b/addons/account/models/account_move.py
index b81fe67616b..7e80b36f463 100644
--- a/addons/account/models/account_move.py
+++ b/addons/account/models/account_move.py
@@ -667,7 +667,7 @@ class AccountMove(models.Model):
         highest_name = self[0]._get_last_sequence(lock=False) if self else False
 
         for move in self:
-            if not highest_name and move == self[0] and not move.posted_before and move.date:
+            if not highest_name and move == self[0] and not move.posted_before and move.date and (not move.name or move.name == '/'):
                 # In the form view, we need to compute a default sequence so that the user can edit
                 # it. We only check the first move as an approximation (enough for new in form view)
                 move._set_next_sequence()