diff --git a/app/views/groups/milestones/index.html.haml b/app/views/groups/milestones/index.html.haml
index 9dd8fa96640..18ea03b25af 100644
--- a/app/views/groups/milestones/index.html.haml
+++ b/app/views/groups/milestones/index.html.haml
@@ -26,9 +26,9 @@
               .pull-right
                 - if can?(current_user, :manage_group, @group)
                   - if milestone.closed?
-                    = link_to 'Reopen Milestone', group_milestone_path(@group, milestone.safe_title, title: milestone.title, milestone: {state_event: :activate }), method: :put, class: "btn btn-small btn-grouped"
+                    = link_to 'Reopen Milestone', group_milestone_path(@group, milestone.safe_title, title: milestone.title, milestone: {state_event: :activate }), method: :put, class: "btn btn-small btn-grouped btn-reopen"
                   - else
-                    = link_to 'Close Milestone', group_milestone_path(@group, milestone.safe_title, title: milestone.title, milestone: {state_event: :close }), method: :put, class: "btn btn-small btn-remove"
+                    = link_to 'Close Milestone', group_milestone_path(@group, milestone.safe_title, title: milestone.title, milestone: {state_event: :close }), method: :put, class: "btn btn-small btn-close"
               %h4
                 = link_to_gfm truncate(milestone.title, length: 100), group_milestone_path(@group, milestone.safe_title, title: milestone.title)
               %div
diff --git a/app/views/groups/milestones/show.html.haml b/app/views/groups/milestones/show.html.haml
index d39870b032c..4b6c00a3247 100644
--- a/app/views/groups/milestones/show.html.haml
+++ b/app/views/groups/milestones/show.html.haml
@@ -3,9 +3,9 @@
   .pull-right
     - if can?(current_user, :manage_group, @group)
       - if @group_milestone.active?
-        = link_to 'Close Milestone', group_milestone_path(@group, @group_milestone.safe_title, title: @group_milestone.title, milestone: {state_event: :close }), method: :put, class: "btn btn-small btn-remove"
+        = link_to 'Close Milestone', group_milestone_path(@group, @group_milestone.safe_title, title: @group_milestone.title, milestone: {state_event: :close }), method: :put, class: "btn btn-small btn-close"
       - else
-        = link_to 'Reopen Milestone', group_milestone_path(@group, @group_milestone.safe_title, title: @group_milestone.title, milestone: {state_event: :activate }), method: :put, class: "btn btn-small btn-grouped"
+        = link_to 'Reopen Milestone', group_milestone_path(@group, @group_milestone.safe_title, title: @group_milestone.title, milestone: {state_event: :activate }), method: :put, class: "btn btn-small btn-grouped btn-reopen"
 
 - if (@group_milestone.total_items_count == @group_milestone.closed_items_count) && @group_milestone.active?
   .alert.alert-success