diff --git a/app/assets/stylesheets/framework/nav.scss b/app/assets/stylesheets/framework/nav.scss
index e890c2e06347300046efef9f66601f5c1286a3f5..28b2a7cfacd786b6c918e02ec308520ee3ff1620 100644
--- a/app/assets/stylesheets/framework/nav.scss
+++ b/app/assets/stylesheets/framework/nav.scss
@@ -443,8 +443,8 @@
   }
 }
 
-.activities {
-  .nav-block {
+.nav-block {
+  &.activities {
     border-bottom: 1px solid $border-color;
 
     .nav-links {
diff --git a/app/views/dashboard/_activities.html.haml b/app/views/dashboard/_activities.html.haml
index 89d991abe548065c9bc3f9c3d535a65a6a1c8634..e1b270a08c25b4b8ea1ac270ce9df6e1fb30ebc2 100644
--- a/app/views/dashboard/_activities.html.haml
+++ b/app/views/dashboard/_activities.html.haml
@@ -1,7 +1,7 @@
 .hidden-xs
   = render "events/event_last_push", event: @last_push
 
-.nav-block
+.nav-block.activities
   .controls
     = link_to dashboard_projects_path(rss_url_options), class: 'btn rss-btn has-tooltip', title: 'Subscribe' do
       %i.fa.fa-rss
diff --git a/app/views/projects/_activity.html.haml b/app/views/projects/_activity.html.haml
index aa0cb3e1a50947a4deffc104054b954d4c4dcb99..f5bb7364d4ada84dbf1f7f502a4af9a90586fe72 100644
--- a/app/views/projects/_activity.html.haml
+++ b/app/views/projects/_activity.html.haml
@@ -1,7 +1,7 @@
 - @no_container = true
 
 %div{ class: container_class }
-  .nav-block.activity-filter-block
+  .nav-block.activity-filter-block.activities
     .controls
       = link_to namespace_project_path(@project.namespace, @project, rss_url_options), title: "Subscribe", class: 'btn rss-btn has-tooltip' do
         = icon('rss')
diff --git a/changelogs/unreleased/32570-project-activity-tab-border.yml b/changelogs/unreleased/32570-project-activity-tab-border.yml
new file mode 100644
index 0000000000000000000000000000000000000000..100a3e6a74dfad010e0c7dd0da8d5035c7cc1ab3
--- /dev/null
+++ b/changelogs/unreleased/32570-project-activity-tab-border.yml
@@ -0,0 +1,4 @@
+---
+title: Fix border-bottom for project activity tab
+merge_request:
+author: