diff --git a/addons/sms/static/src/scss/thread.scss b/addons/sms/static/src/scss/thread.scss
index ba4e54386c7..4d7d653eb02 100644
--- a/addons/sms/static/src/scss/thread.scss
+++ b/addons/sms/static/src/scss/thread.scss
@@ -1,4 +1,4 @@
-i.o_thread_message_sms.o_thread_message_sms_error {
+.o_thread_message_sms.o_thread_message_sms_error {
     color: red;
     opacity: 1;
     cursor: pointer;
diff --git a/addons/sms/wizard/sms_composer.py b/addons/sms/wizard/sms_composer.py
index 841ef609597..8c2db1eb7f0 100644
--- a/addons/sms/wizard/sms_composer.py
+++ b/addons/sms/wizard/sms_composer.py
@@ -111,7 +111,7 @@ class SendSMS(models.TransientModel):
                 if len(records) == 1:
                     self.recipient_description = '%s (%s)' % (
                         res[records.id]['partner'].name or records.display_name,
-                        res[records.id]['sanitized']
+                        res[records.id]['sanitized'] or _("Invalid number")
                     )
             else:
                 self.recipient_invalid_count = 0 if (self.sanitized_numbers or (self.composition_mode == 'mass' and self.use_active_domain)) else 1