diff --git a/django/contrib/flatpages/forms.py b/django/contrib/flatpages/forms.py
index e0a63e4323..a848875a9f 100644
--- a/django/contrib/flatpages/forms.py
+++ b/django/contrib/flatpages/forms.py
@@ -35,7 +35,7 @@ class FlatpageForm(forms.ModelForm):
             for site in sites:
                 if same_url.filter(sites=site).exists():
                     raise forms.ValidationError(
-                        _('Flatpage with url %(url)s already exists for site %(site)s' %
-                          {'url': url, 'site': site}))
+                        _('Flatpage with url %(url)s already exists for site %(site)s') %
+                          {'url': url, 'site': site})
 
         return super(FlatpageForm, self).clean()