diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 14bfed6c8..3e5ab85bf 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -96,13 +96,15 @@ def sponsorship_level_title(level)
   end
 
   # Admin-page subject of a member activity: the entity the action was about.
-  # Returns nil when the subject is the member themselves (e.g. logins, bans).
+  # Returns nil when the subject is the member themselves (e.g. logins).
+  # Ban and MemberNote records have no admin show route, so link their member.
   def activity_subject(activity)
     case (trackable = activity.trackable)
     when WorkshopInvitation then trackable.workshop
     when Invitation then trackable.event
     when MeetingInvitation then trackable.meeting
     when Member then nil
+    when Ban, MemberNote then trackable.member
     else trackable
     end
   end
diff --git a/spec/controllers/admin/members_controller_spec.rb b/spec/controllers/admin/members_controller_spec.rb
index 3b3267b8a..b850d8d3e 100644
--- a/spec/controllers/admin/members_controller_spec.rb
+++ b/spec/controllers/admin/members_controller_spec.rb
@@ -171,6 +171,27 @@
 
         expect(response.body).to include("href=\"#{admin_event_path(invitation.event)}\"")
       end
+
+      it 'links the banned member for a ban activity' do
+        banned = Fabricate(:member)
+        ban = Fabricate(:ban, member: banned)
+        MemberActivityRecorder.record(actor: member, key: 'member.banned',
+                                      trackable: ban, recipient: banned)
+
+        get :show, params: { id: member.id }
+
+        expect(response.body).to include("href=\"#{admin_member_path(banned)}\"")
+      end
+
+      it 'links the noted member for a member-note activity' do
+        note = Fabricate(:member_note, author: member)
+        MemberActivityRecorder.record(actor: member, key: 'member_note.created',
+                                      trackable: note, recipient: note.member)
+
+        get :show, params: { id: member.id }
+
+        expect(response.body).to include("href=\"#{admin_member_path(note.member)}\"")
+      end
     end
   end
 
diff --git a/spec/helpers/application_helper_spec.rb b/spec/helpers/application_helper_spec.rb
index 3dc2bde3f..6d56f7ef2 100644
--- a/spec/helpers/application_helper_spec.rb
+++ b/spec/helpers/application_helper_spec.rb
@@ -63,6 +63,30 @@
     end
   end
 
+  describe '#activity_subject' do
+    def activity_with(trackable)
+      PublicActivity::Activity.new(key: 'test', trackable:)
+    end
+
+    it 'returns the banned member for a ban, since bans have no admin route' do
+      ban = Fabricate(:ban, member: Fabricate(:member))
+
+      expect(helper.activity_subject(activity_with(ban))).to eq(ban.member)
+    end
+
+    it 'returns the noted member for a member note, since notes have no admin route' do
+      note = Fabricate(:member_note)
+
+      expect(helper.activity_subject(activity_with(note))).to eq(note.member)
+    end
+
+    it 'returns nil when the trackable is the member themselves' do
+      member = Fabricate(:member)
+
+      expect(helper.activity_subject(activity_with(member))).to be_nil
+    end
+  end
+
   describe '#stylesheet_link_tag and #javascript_include_tag' do
     around do |example|
       ApplicationHelper::HEAD_ASSET_TAG_CACHE.clear