diff --git a/odoo/models.py b/odoo/models.py
index 577ef080197..3c9daa02ce9 100644
--- a/odoo/models.py
+++ b/odoo/models.py
@@ -4474,7 +4474,7 @@ class BaseModel(object):
             # mark missing records in cache with a failed value
             exc = MissingError(
                 _("Record does not exist or has been deleted.")
-                + '\n\n({} {}, {} {})'.format(_('Records:'), (self - existing).ids[:6], _('User:'), self._uid)
+                + u'\n\n({} {}, {} {})'.format(_('Records:'), (self - existing).ids[:6], _('User:'), self._uid)
             )
             (self - existing)._cache.update(FailedValue(exc))
         return existing