diff --git a/app/controllers/concerns/web_app_controller_concern.rb b/app/controllers/concerns/web_app_controller_concern.rb
index 9485ecda49..249bb20a25 100644
--- a/app/controllers/concerns/web_app_controller_concern.rb
+++ b/app/controllers/concerns/web_app_controller_concern.rb
@@ -7,7 +7,6 @@ module WebAppControllerConcern
     vary_by 'Accept, Accept-Language, Cookie'
 
     before_action :redirect_unauthenticated_to_permalinks!
-    before_action :set_app_body_class
 
     content_security_policy do |p|
       policy = ContentSecurityPolicy.new
@@ -24,10 +23,6 @@ module WebAppControllerConcern
     !(ENV['ONE_CLICK_SSO_LOGIN'] == 'true' && ENV['OMNIAUTH_ONLY'] == 'true' && Devise.omniauth_providers.length == 1) && current_user.nil?
   end
 
-  def set_app_body_class
-    @body_classes = 'app-body'
-  end
-
   def redirect_unauthenticated_to_permalinks!
     return if user_signed_in? && current_account.moved_to_account_id.nil?
 
diff --git a/app/views/shared/_web_app.html.haml b/app/views/shared/_web_app.html.haml
index 89d6ee567d..4f9a20a9f4 100644
--- a/app/views/shared/_web_app.html.haml
+++ b/app/views/shared/_web_app.html.haml
@@ -1,3 +1,4 @@
+- content_for :body_classes, 'app-body'
 - content_for :header_tags do
   - if user_signed_in?
     = preload_pack_asset 'features/compose.js'
diff --git a/spec/system/about_spec.rb b/spec/system/about_spec.rb
index f832802f91..d7fd7f51a1 100644
--- a/spec/system/about_spec.rb
+++ b/spec/system/about_spec.rb
@@ -8,5 +8,6 @@ RSpec.describe 'About page' do
 
     expect(page)
       .to have_css('noscript', text: /Mastodon/)
+      .and have_css('body', class: 'app-body')
   end
 end
diff --git a/spec/system/home_spec.rb b/spec/system/home_spec.rb
index c1ce4e1726..0838b3d8e7 100644
--- a/spec/system/home_spec.rb
+++ b/spec/system/home_spec.rb
@@ -11,6 +11,7 @@ RSpec.describe 'Home page' do
 
       expect(page)
         .to have_css('noscript', text: /Mastodon/)
+        .and have_css('body', class: 'app-body')
     end
   end
 
@@ -20,6 +21,7 @@ RSpec.describe 'Home page' do
 
       expect(page)
         .to have_css('noscript', text: /Mastodon/)
+        .and have_css('body', class: 'app-body')
     end
   end
 end
diff --git a/spec/system/privacy_spec.rb b/spec/system/privacy_spec.rb
index 631440ebb2..f2e4d5a993 100644
--- a/spec/system/privacy_spec.rb
+++ b/spec/system/privacy_spec.rb
@@ -8,5 +8,6 @@ RSpec.describe 'Privacy policy page' do
 
     expect(page)
       .to have_css('noscript', text: /Mastodon/)
+      .and have_css('body', class: 'app-body')
   end
 end
diff --git a/spec/system/tags_spec.rb b/spec/system/tags_spec.rb
index f39c6bf0d8..9da5768c7f 100644
--- a/spec/system/tags_spec.rb
+++ b/spec/system/tags_spec.rb
@@ -13,6 +13,7 @@ RSpec.describe 'Tags' do
 
       expect(page)
         .to have_css('noscript', text: /Mastodon/)
+        .and have_css('body', class: 'app-body')
         .and have_private_cache_control
     end
   end