diff --git a/addons/account/wizard/account_invoice_send.py b/addons/account/wizard/account_invoice_send.py
index 99d745ff94b98a1d064d5e17106cb24453c0574b..ce4dab563178041ce67a17e5a36625e389f4d9cf 100644
--- a/addons/account/wizard/account_invoice_send.py
+++ b/addons/account/wizard/account_invoice_send.py
@@ -44,13 +44,14 @@ class AccountInvoiceSend(models.TransientModel):
     @api.onchange('invoice_ids')
     def _compute_composition_mode(self):
         for wizard in self:
-            wizard.composition_mode = 'comment' if len(wizard.invoice_ids) == 1 else 'mass_mail'
+            wizard.composer_id.composition_mode = 'comment' if len(wizard.invoice_ids) == 1 else 'mass_mail'
 
     @api.onchange('template_id')
     def onchange_template_id(self):
-        if self.composer_id:
-            self.composer_id.template_id = self.template_id.id
-            self.composer_id.onchange_template_id_wrapper()
+        for wizard in self:
+            if wizard.composer_id:
+                wizard.composer_id.template_id = wizard.template_id.id
+                wizard.composer_id.onchange_template_id_wrapper()
 
     @api.onchange('is_email')
     def onchange_is_email(self):