diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 05583e520c0..338b7069055 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -181,7 +181,7 @@ module ApplicationHelper
     result = ApplicationHelper.extra_body_classes.to_a
 
     if @category && @category.url.present?
-      result << "category-#{@category.url.sub(/^\/c\//, '').gsub(/\//, '-')}"
+      result << "category-#{@category.slug_path.join('-')}"
     end
 
     if current_user.present? &&
diff --git a/spec/requests/list_controller_spec.rb b/spec/requests/list_controller_spec.rb
index c73ec252f21..890b8b9c07e 100644
--- a/spec/requests/list_controller_spec.rb
+++ b/spec/requests/list_controller_spec.rb
@@ -941,4 +941,15 @@ RSpec.describe ListController do
       expect(response.parsed_body['topic_list']['topics'].map { |t| t['id'] }).to contain_exactly(topic2.id)
     end
   end
+
+  describe "body class" do
+    it "pre-renders the correct body class for categories" do
+      c = Fabricate(:category, slug: 'myparentslug')
+      sub_c = Fabricate(:category, parent_category: c, slug: 'mychildslug')
+
+      get "/c/#{c.slug}/#{sub_c.slug}/#{sub_c.id}"
+
+      expect(response.body).to have_tag "body", with: { class: "category-myparentslug-mychildslug" }
+    end
+  end
 end