diff --git a/chrono/manager/forms.py b/chrono/manager/forms.py
index 04a035f5..59a0c8d7 100644
--- a/chrono/manager/forms.py
+++ b/chrono/manager/forms.py
@@ -834,7 +834,7 @@ class MeetingTypeForm(forms.ModelForm):
                     and mt.duration == self.instance.duration
                 ):
                     raise ValidationError(
-                        _('This meetingtype is used by a virtual agenda: %s' % virtual_agenda)
+                        _('This meetingtype is used by a virtual agenda: %s') % virtual_agenda
                     )