diff --git a/app/views/projects/milestones/_form.html.haml b/app/views/projects/milestones/_form.html.haml
index 5f2057df4aabab3ff38fa73854a4ccfb6300e38a..9b0508d8cb5d95c71592e23d9762d04aafced2ed 100644
--- a/app/views/projects/milestones/_form.html.haml
+++ b/app/views/projects/milestones/_form.html.haml
@@ -1,6 +1,6 @@
 = form_for [@project, @milestone],
            html: { class: 'milestone-form common-note-form js-quick-submit js-requires-input' } do |f|
-  = form_errors(@milestone)
+  = form_errors(@milestone, pajamas_alert: true)
   .form-group.row
     .col-form-label.col-sm-2
       = f.label :title, _('Title')
diff --git a/spec/features/milestone_spec.rb b/spec/features/milestone_spec.rb
index 5bbd89f1b8839ae5260b9280c1b25afd316ebf1a..2a1ea1a4e736110749721231dfc20ab0f140d6b9 100644
--- a/spec/features/milestone_spec.rb
+++ b/spec/features/milestone_spec.rb
@@ -51,7 +51,7 @@
       end
       find('input[name="commit"]').click
 
-      expect(find('.alert-danger')).to have_content('already being used for another group or project milestone.')
+      expect(find('.gl-alert-danger')).to have_content('already being used for another group or project milestone.')
     end
 
     it 'displays validation message when there is a group milestone with same title' do