diff --git a/app/models/wiki_page.rb b/app/models/wiki_page.rb
index 20531edac..8dac41603 100644
--- a/app/models/wiki_page.rb
+++ b/app/models/wiki_page.rb
@@ -162,10 +162,6 @@ class WikiPage < ApplicationRecord
     name.to_s.unicode_normalize(:nfkc).normalize_whitespace.gsub(/[[:space:]]+/, "_").squeeze("_").gsub(/\A_|_\z/, "")
   end
 
-  def category_name
-    tag&.category
-  end
-
   def pretty_title
     title.tr("_", " ")
   end
diff --git a/app/policies/wiki_page_policy.rb b/app/policies/wiki_page_policy.rb
index ca1bf5324..81b897fcc 100644
--- a/app/policies/wiki_page_policy.rb
+++ b/app/policies/wiki_page_policy.rb
@@ -14,12 +14,4 @@ class WikiPagePolicy < ApplicationPolicy
   def permitted_attributes
     [:title, :body, :other_names, :other_names_string, :is_deleted, (:is_locked if can_edit_locked?)].compact
   end
-
-  def api_attributes
-    super + [:category_name]
-  end
-
-  def html_data_attributes
-    super + [:category_name]
-  end
 end
diff --git a/app/views/wiki_page_versions/diff.html.erb b/app/views/wiki_page_versions/diff.html.erb
index c7e063eff..5866e9331 100644
--- a/app/views/wiki_page_versions/diff.html.erb
+++ b/app/views/wiki_page_versions/diff.html.erb
@@ -4,7 +4,7 @@
 <%= render "wiki_pages/sidebar" %>
 
 <% content_for(:content) do %>
-  <h1>Wiki Page Version Comparison:  <%= link_to @thispage.title, wiki_page_versions_path(search: { wiki_page_id: @thispage.wiki_page_id }, type: params[:type], anchor: "wiki-page-version-#{@thispage.id}"), class: "tag-type-#{@thispage.wiki_page.category_name}" %></h1>
+  <h1>Wiki Page Version Comparison: <%= link_to @thispage.title, wiki_page_versions_path(search: { wiki_page_id: @thispage.wiki_page_id }, type: params[:type], anchor: "wiki-page-version-#{@thispage.id}"), class: "tag-type-#{@thispage.wiki_page.tag.category}" %></h1>
 
   <% if params[:type].present? %>
     <%= render "versions/types" %>