diff --git a/Gemfile b/Gemfile
index 90c096f93e7..6cd14670fb8 100644
--- a/Gemfile
+++ b/Gemfile
@@ -295,7 +295,7 @@ group :test do
   gem "rails-controller-testing", "~> 1.0.2"
 
   gem "capybara", "~> 3.40.0"
-  gem "capybara_accessible_selectors", git: "https://github.com/citizensadvice/capybara_accessible_selectors", tag: "v0.15.0"
+  gem "capybara_accessible_selectors", git: "https://github.com/citizensadvice/capybara_accessible_selectors", tag: "v0.16.0"
   gem "capybara-screenshot", "~> 1.0.17"
   gem "cuprite", "~> 0.17.0"
   gem "rspec-wait"
diff --git a/Gemfile.lock b/Gemfile.lock
index 4a9df999d10..b3a20bfd480 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 GIT
   remote: https://github.com/citizensadvice/capybara_accessible_selectors
-  revision: 5b9ce7840d04270e99f4f0cb03989e05437326a6
-  tag: v0.15.0
+  revision: 568699fc71b6648e7186a4ac77bba072447c131e
+  tag: v0.16.0
   specs:
     capybara_accessible_selectors (0.15.0)
       capybara (~> 3.36)
diff --git a/app/components/table_component.html.erb b/app/components/table_component.html.erb
index 17e2a3410b9..27c53b728d6 100644
--- a/app/components/table_component.html.erb
+++ b/app/components/table_component.html.erb
@@ -42,7 +42,7 @@ See COPYRIGHT and LICENSE files for more details.
               <% if sortable_column?(name) %>
                 <%= helpers.sort_header_tag(name, **options) %>
               <% else %>
-                <th>
+                <th aria-label="<%= options[:caption] %>">
                   <div class="generic-table--sort-header-outer">
                     <div class="generic-table--sort-header">
                       <span>
diff --git a/app/helpers/sort_helper.rb b/app/helpers/sort_helper.rb
index 3fd55d4e29a..982b0524c57 100644
--- a/app/helpers/sort_helper.rb
+++ b/app/helpers/sort_helper.rb
@@ -338,7 +338,7 @@ module SortHelper
 
   # Extracts the given `options` and provides them to a block.
   # See #sort_header_tag and #sort_header_with_action_menu for usage examples.
-  def with_sort_header_options(column, allowed_params: nil, with_title: false, **options)
+  def with_sort_header_options(column, allowed_params: nil, with_title: false, **options) # rubocop:disable Metrics/AbcSize
     caption = get_caption(column, options)
 
     default_order = options.delete(:default_order) || "asc"
@@ -349,6 +349,12 @@ module SortHelper
     options[:title] = sort_header_title(column, caption, options) if with_title
     options[:icon_only_header] = column == :favorited
 
+    # Give the header cell an explicit accessible name equal to the plain caption.
+    # Without it, the column header's accessible name is derived from its contents,
+    # which can include the action menu trigger text and is uppercased by the
+    # `text-transform` styling, neither of which should be part of the name.
+    options[:"aria-label"] = caption if caption.present?
+
     within_sort_header_tag_hierarchy(options, sort_class(column)) do
       yield(column, caption, default_order, allowed_params:, param:, lang:, title: options[:title],
                                             sortable: options.fetch(:sortable, false), data:)
diff --git a/app/views/workflows/summaries/show.html.erb b/app/views/workflows/summaries/show.html.erb
index f5ed8bcff9e..3add4663a34 100644
--- a/app/views/workflows/summaries/show.html.erb
+++ b/app/views/workflows/summaries/show.html.erb
@@ -45,7 +45,7 @@ See COPYRIGHT and LICENSE files for more details.
             <tr>
               <th><div class="generic-table--empty-header"></div></th>
               <% @roles.each do |role| %>
-                <th>
+                <th aria-label="<%= role.name %>">
                   <div class="generic-table--sort-header-outer">
                     <div class="generic-table--sort-header">
                         <%= content_tag(role.builtin? ? "em" : "span", h(role.name)) %>
diff --git a/frontend/src/app/features/work-packages/components/wp-table/wp-table.component.html b/frontend/src/app/features/work-packages/components/wp-table/wp-table.component.html
index ddd77c1e302..f2e3fa4ac1f 100644
--- a/frontend/src/app/features/work-packages/components/wp-table/wp-table.component.html
+++ b/frontend/src/app/features/work-packages/components/wp-table/wp-table.component.html
@@ -49,6 +49,7 @@
               }
               @for (column of columns; track column.href) {
                 <th
+                  [attr.aria-label]="column.name"
                   [ngClass]="{'-max': column.id === 'subject', '-min-200': ['estimatedTime', 'remainingTime'].includes(column.id) }"
                   class="wp-table--table-header">
                   <sortHeader [headerColumn]="column"
diff --git a/modules/backlogs/spec/components/backlogs/sprint_component_spec.rb b/modules/backlogs/spec/components/backlogs/sprint_component_spec.rb
index f9f489f504f..7c2876a089a 100644
--- a/modules/backlogs/spec/components/backlogs/sprint_component_spec.rb
+++ b/modules/backlogs/spec/components/backlogs/sprint_component_spec.rb
@@ -259,8 +259,8 @@ RSpec.describe Backlogs::SprintComponent, type: :component do
           rendered_component
 
           expect(menu_items).to eq(["Edit sprint", "Add work package", "Sprint board", "Burndown chart"])
-          expect(page).to have_list_item position: 2, role: "presentation"
-          expect(page).to have_list_item position: 4, role: "presentation"
+          # The three item groups are separated by presentation-only dividers.
+          expect(page).to have_css("li[role='presentation']", count: 2)
         end
       end
     end
diff --git a/modules/storages/spec/features/storages/project_settings/oauth_access_grant_spec.rb b/modules/storages/spec/features/storages/project_settings/oauth_access_grant_spec.rb
index dfdf55ec049..47174f2301a 100644
--- a/modules/storages/spec/features/storages/project_settings/oauth_access_grant_spec.rb
+++ b/modules/storages/spec/features/storages/project_settings/oauth_access_grant_spec.rb
@@ -67,6 +67,7 @@ RSpec.describe "OAuth Access Grant Nudge upon adding a storage to a project",
 
   it "adds a storage, nudges the project admin to grant OAuth access" do
     visit external_file_storages_project_settings_project_storages_path(project_id: project)
+    expect(page).to have_heading "Files"
 
     click_on("Storage")
 
@@ -76,8 +77,7 @@ RSpec.describe "OAuth Access Grant Nudge upon adding a storage to a project",
     expect(page).to have_checked_field("New folder with automatically managed permissions")
     click_on("Add")
 
-    expect(page).to have_heading "Files"
-    expect(page).to have_text(storage.name)
+    expect(page).to have_selector(:table_row, [storage.name])
 
     within_test_selector("oauth-access-grant-nudge-modal") do
       expect(page).to be_axe_clean
diff --git a/modules/team_planner/spec/support/components/add_existing_pane.rb b/modules/team_planner/spec/support/components/add_existing_pane.rb
index f91eee78720..35741a731f9 100644
--- a/modules/team_planner/spec/support/components/add_existing_pane.rb
+++ b/modules/team_planner/spec/support/components/add_existing_pane.rb
@@ -69,7 +69,9 @@ module Components
 
     def drag_wp_to_date(work_package, date)
       wp_card = card(work_package)
-      day_header = page.find(:columnheader, exact_text: date.strftime("%02d %A"))
+      # The FullCalendar timeline day headers are not exposed as columnheaders
+      # (their table has a presentation role), so target the labelled slot by date.
+      day_header = page.find(".fc-timeline-slot-label[data-date='#{date.iso8601}']")
       drag_n_drop_element(from: wp_card, to: day_header, offset_y: day_header.native.size.height)
     end
 
diff --git a/modules/webhooks/spec/components/webhooks/outgoing/webhooks/row_component_spec.rb b/modules/webhooks/spec/components/webhooks/outgoing/webhooks/row_component_spec.rb
index 73d67c712f1..4ff1b3e529e 100644
--- a/modules/webhooks/spec/components/webhooks/outgoing/webhooks/row_component_spec.rb
+++ b/modules/webhooks/spec/components/webhooks/outgoing/webhooks/row_component_spec.rb
@@ -95,8 +95,8 @@ RSpec.describe Webhooks::Outgoing::Webhooks::RowComponent, type: :component do
       it "renders events list grouped by Resource", :aggregate_failures do
         expect(rendered_component).to have_list do |list|
           expect(list).to have_list_item count: 2
-          expect(list).to have_list_item "Projects (created)"
-          expect(list).to have_list_item "Work package comments (comment)"
+          expect(list).to have_list_item "Projects (Created)"
+          expect(list).to have_list_item "Work package comments (Comment)"
         end
       end
     end
diff --git a/spec/components/op_primer/list_component_spec.rb b/spec/components/op_primer/list_component_spec.rb
index e0f299c0630..4501628e94c 100644
--- a/spec/components/op_primer/list_component_spec.rb
+++ b/spec/components/op_primer/list_component_spec.rb
@@ -112,9 +112,8 @@ RSpec.describe OpPrimer::ListComponent, type: :component do
     end
 
     it "renders list items" do
-      expect(rendered_component).to have_list_item count: 3
+      expect(rendered_component).to have_list_item count: 2
       expect(rendered_component).to have_list_item position: 1, text: "List item 1"
-      expect(rendered_component).to have_list_item position: 2, role: "presentation"
       expect(rendered_component).to have_list_item position: 3, text: "List item 2"
     end
   end
diff --git a/spec/features/admin/custom_fields/work_packages/hierarchy_spec.rb b/spec/features/admin/custom_fields/work_packages/hierarchy_spec.rb
index 818d20522fb..8c82b9a8085 100644
--- a/spec/features/admin/custom_fields/work_packages/hierarchy_spec.rb
+++ b/spec/features/admin/custom_fields/work_packages/hierarchy_spec.rb
@@ -144,7 +144,7 @@ RSpec.describe "work package custom fields of type hierarchy", :js do
 
     # Finally, we delete the custom field ... I'm done with this ...
     custom_field_index_page.visit!
-    expect(page).to have_list_item(hierarchy_name)
+    expect(page).to have_row(hierarchy_name)
     within("tr", text: hierarchy_name) { accept_prompt { click_on "Delete" } }
     expect(page).to have_no_text(hierarchy_name)
 
diff --git a/spec/features/projects/edit_settings_spec.rb b/spec/features/projects/edit_settings_spec.rb
index c5bf33d26e7..1108994d060 100644
--- a/spec/features/projects/edit_settings_spec.rb
+++ b/spec/features/projects/edit_settings_spec.rb
@@ -167,7 +167,7 @@ RSpec.describe "Projects", "editing settings", :js do
       within_section "Status" do
         click_on "Edit status"
 
-        within :menu, "Not set" do
+        within :menu, "Edit status" do
           find(:menuitem, "Not started").click
         end
       end
@@ -179,7 +179,7 @@ RSpec.describe "Projects", "editing settings", :js do
         expect(button).to have_text "Not started"
         button.click
 
-        expect(find(:menu, "Not started")).to have_selector :menuitem, "Not started", aria: { current: true }
+        expect(find(:menu, "Edit status")).to have_selector :menuitem, "Not started", aria: { current: true }
       end
     end
 
@@ -187,7 +187,7 @@ RSpec.describe "Projects", "editing settings", :js do
       within_section "Status" do
         click_on "Edit status"
 
-        within :menu, "Not set" do
+        within :menu, "Edit status" do
           find(:menuitem, "Finished").click
         end
       end
@@ -197,7 +197,7 @@ RSpec.describe "Projects", "editing settings", :js do
       within_section "Status" do
         click_on "Edit status"
 
-        within :menu, "Finished" do
+        within :menu, "Edit status" do
           find(:menuitem, "Not set").click
         end
       end
@@ -209,7 +209,7 @@ RSpec.describe "Projects", "editing settings", :js do
         expect(button).to have_text "Not set"
         button.click
 
-        expect(find(:menu, "Not set")).to have_selector :menuitem, "Not set", aria: { current: true }
+        expect(find(:menu, "Edit status")).to have_selector :menuitem, "Not set", aria: { current: true }
       end
     end
 
diff --git a/spec/features/work_packages/table/configuration_modal/column_spec.rb b/spec/features/work_packages/table/configuration_modal/column_spec.rb
index 222accbcb51..f38bdca1592 100644
--- a/spec/features/work_packages/table/configuration_modal/column_spec.rb
+++ b/spec/features/work_packages/table/configuration_modal/column_spec.rb
@@ -82,7 +82,7 @@ RSpec.describe "Work Package table configuration modal columns spec", :js do
         expect(page).to have_selector :columnheader, text: /.+/, count: 3
         expect(page).to have_selector :columnheader, "ID"
         expect(page).to have_selector :columnheader, "Subject"
-        expect(page).to have_selector :columnheader, "Project", colindex: 2
+        expect(page).to have_selector :columnheader, "Project", colindex: 4
       end
     end
   end
diff --git a/spec/helpers/sort_helper_spec.rb b/spec/helpers/sort_helper_spec.rb
index 43bf9e5cbfe..4ec596691a0 100644
--- a/spec/helpers/sort_helper_spec.rb
+++ b/spec/helpers/sort_helper_spec.rb
@@ -145,7 +145,7 @@ RSpec.describe SortHelper do
 
     it "renders a th with a sort link" do
       expect(output).to be_html_eql(<<-HTML)
-        <th title="Sort by &quot;Id&quot;">
+        <th title="Sort by &quot;Id&quot;" aria-label="Id">
           <div class="generic-table--sort-header-outer">
             <div class="generic-table--sort-header">
               <span>
@@ -165,7 +165,7 @@ RSpec.describe SortHelper do
 
       it "adds the sort class" do
         expect(output).to be_html_eql(<<-HTML)
-          <th title="Ascending sorted by &quot;Id&quot;">
+          <th title="Ascending sorted by &quot;Id&quot;" aria-label="Id">
             <div class="generic-table--sort-header-outer">
               <div class="generic-table--sort-header">
                 <span class="sort asc">
@@ -187,7 +187,7 @@ RSpec.describe SortHelper do
 
       it "adds the sort class" do
         expect(output).to be_html_eql(<<-HTML)
-          <th title="Descending sorted by &quot;Id&quot;">
+          <th title="Descending sorted by &quot;Id&quot;" aria-label="Id">
             <div class="generic-table--sort-header-outer">
               <div class="generic-table--sort-header">
                 <span class="sort desc">
@@ -219,7 +219,7 @@ RSpec.describe SortHelper do
       context "when not given allowed parameters" do
         it "copies default ones to the link" do
           expect(output).to be_html_eql(<<-HTML)
-            <th title="Sort by &quot;Id&quot;">
+            <th title="Sort by &quot;Id&quot;" aria-label="Id">
               <div class="generic-table--sort-header-outer">
                 <div class="generic-table--sort-header">
                   <span>
@@ -240,7 +240,7 @@ RSpec.describe SortHelper do
 
         it "copies them to the link" do
           expect(output).to be_html_eql(<<-HTML)
-            <th title="Sort by &quot;Id&quot;">
+            <th title="Sort by &quot;Id&quot;" aria-label="Id">
               <div class="generic-table--sort-header-outer">
                 <div class="generic-table--sort-header">
                   <span>
@@ -262,7 +262,7 @@ RSpec.describe SortHelper do
 
       it "includes the passed data param in the link" do
         expect(output).to be_html_eql(<<~HTML)
-          <th title="Sort by &quot;Id&quot;">
+          <th title="Sort by &quot;Id&quot;" aria-label="Id">
             <div class="generic-table--sort-header-outer">
               <div class="generic-table--sort-header">
                 <span>
diff --git a/spec/support/capybara/additional_accessible_selectors.rb b/spec/support/capybara/additional_accessible_selectors.rb
index 1a7d338377c..a16c57d0818 100644
--- a/spec/support/capybara/additional_accessible_selectors.rb
+++ b/spec/support/capybara/additional_accessible_selectors.rb
@@ -28,49 +28,20 @@
 # See COPYRIGHT and LICENSE files for more details.
 #++
 
-# Workaround to support role filters in component specs. This should be fixed upstream.
-Capybara::Node::Simple.class_eval do
-  def role
-    self[:role]
-  end
+CapybaraAccessibleSelectors.add_role_selector(:list, within: true) do
+  filter_set(:capybara_accessible_selectors, %i[aria described_by])
 end
 
-Capybara.add_selector(:list) do
-  xpath do |*|
-    XPath.descendant[[
-      XPath.self(:ul),
-      XPath.self(:ol)
-    ].reduce(:|)]
-  end
-
-  locator_filter skip_if: nil do |node, locator, exact:, **|
-    method = exact ? :eql? : :include?
-    if node[:"aria-labelledby"]
-      CapybaraAccessibleSelectors::Helpers.element_labelledby(node).public_send(method, locator)
-    elsif node[:"aria-label"]
-      node[:"aria-label"].public_send(method, locator.to_s)
-    end
-  end
-
-  filter_set(:capybara_accessible_selectors, %i[aria role described_by])
-end
-
-Capybara.add_selector(:list_item) do
-  label "list item"
-
-  xpath do |*|
-    XPath.descendant[XPath.self(:li)]
-  end
-
-  expression_filter(:position) do |xpath, position|
-    position ? "#{xpath}[#{position}]" : xpath
+CapybaraAccessibleSelectors.add_role_selector(:list_item, role: :listitem, within: true, content_fallback: true) do
+  expression_filter(:position, skip_if: nil) do |xpath, position|
+    xpath[position]
   end
 
   describe_expression_filters do |position: nil, **|
     position ? " at position #{position}" : ""
   end
 
-  filter_set(:capybara_accessible_selectors, %i[aria role described_by])
+  filter_set(:capybara_accessible_selectors, %i[aria described_by])
 end
 
 module Capybara