diff --git a/addons/account/models/account_move.py b/addons/account/models/account_move.py
index eb5852eb043..6994a6dcc90 100644
--- a/addons/account/models/account_move.py
+++ b/addons/account/models/account_move.py
@@ -3472,7 +3472,7 @@ class AccountMoveLine(models.Model):
         help="The move of this entry line.")
     move_name = fields.Char(string='Number', related='move_id.name', store=True, index=True)
     date = fields.Date(related='move_id.date', store=True, readonly=True, index=True, copy=False, group_operator='min')
-    ref = fields.Char(related='move_id.ref', store=True, copy=False, index=True, readonly=False)
+    ref = fields.Char(related='move_id.ref', store=True, copy=False, index=True, readonly=True)
     parent_state = fields.Selection(related='move_id.state', store=True, readonly=True)
     journal_id = fields.Many2one(related='move_id.journal_id', store=True, index=True, copy=False)
     company_id = fields.Many2one(related='move_id.company_id', store=True, readonly=True)