diff --git a/src/mail/0.0.0/pre-report-migration.py b/src/mail/0.0.0/pre-report-migration.py
index 9d8b425f..ac7212a6 100644
--- a/src/mail/0.0.0/pre-report-migration.py
+++ b/src/mail/0.0.0/pre-report-migration.py
@@ -22,7 +22,7 @@ def migrate(cr, version):
 
 
 class MailMessage(models.Model):
-    _inherit = ["mail.message"]
+    _inherit = "mail.message"
     _module = "mail"
 
     @model_cr