diff --git a/account_usability/__openerp__.py b/account_usability/__openerp__.py
index b62613b..c795a17 100644
--- a/account_usability/__openerp__.py
+++ b/account_usability/__openerp__.py
@@ -23,7 +23,7 @@
 
 {
     'name': 'Account Usability',
-    'version': '0.1',
+    'version': '0.2',
     'category': 'Accounting & Finance',
     'license': 'AGPL-3',
     'summary': 'Small usability enhancements in account module',
diff --git a/account_usability/account.py b/account_usability/account.py
index 1b6d30d..e214035 100644
--- a/account_usability/account.py
+++ b/account_usability/account.py
@@ -62,6 +62,23 @@ class AccountInvoice(models.Model):
             res['value']['period_id'] = False
         return res
 
+    # I really hate to see a "/" in the 'name' field of the account.move.line
+    # generated from customer invoices linked to the partners' account because:
+    # 1) the label of an account move line is an important field, we can't
+    #    write a rubbish '/' in it !
+    # 2) the 'name' field of the account.move.line is used in the overdue letter,
+    # and '/' is not meaningful for our customer !
+    @api.multi
+    def action_number(self):
+        res = super(AccountInvoice, self).action_number()
+        for inv in self:
+            if inv.type in ('out_invoice', 'out_refund'):
+                self._cr.execute(
+                    "UPDATE account_move_line SET name=%s WHERE "
+                    "move_id=%s AND name='/'", (inv.number, inv.move_id.id))
+                self.invalidate_cache()
+        return res
+
 
 class AccountFiscalYear(models.Model):
     _inherit = 'account.fiscalyear'
diff --git a/account_usability/migrations/8.0.0.2/pre-migration.py b/account_usability/migrations/8.0.0.2/pre-migration.py
new file mode 100644
index 0000000..1b21694
--- /dev/null
+++ b/account_usability/migrations/8.0.0.2/pre-migration.py
@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+# © 2016 Akretion (Alexis de Lattre <alexis.delattre@akretion.com>)
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+def migrate(cr, version):
+    if not version:
+        return
+
+    # cf the inherit of action_number() of account.invoice
+    # in account_usability/account.py
+    cr.execute(
+        "UPDATE account_move_line SET name=ref WHERE name='/' "
+        "AND ref is not null AND journal_id in "
+        "(SELECT id FROM account_journal WHERE type in ('sale', 'sale_refund'))")