diff --git a/app/models/category_list.rb b/app/models/category_list.rb
index 83698d89872..aba935d8fb6 100644
--- a/app/models/category_list.rb
+++ b/app/models/category_list.rb
@@ -31,8 +31,8 @@ class CategoryList
     @guardian = guardian || Guardian.new
     @options = options
 
-    find_relevant_topics if options[:include_topics]
     find_categories
+    find_relevant_topics if options[:include_topics]
 
     prune_empty
     find_user_data
@@ -71,17 +71,18 @@ class CategoryList
   private
 
   def find_relevant_topics
-    @topics_by_id = {}
-    @topics_by_category_id = {}
-
-    category_featured_topics = CategoryFeaturedTopic.select(%i[category_id topic_id]).order(:rank)
-
     @all_topics =
-      Topic.where(id: category_featured_topics.map(&:topic_id)).includes(
-        :shared_draft,
-        :category,
-        { topic_thumbnails: %i[optimized_image upload] },
-      )
+      Topic
+        .secured(@guardian)
+        .joins(
+          "INNER JOIN category_featured_topics ON topics.id = category_featured_topics.topic_id",
+        )
+        .where("category_featured_topics.category_id IN (?)", categories_with_descendants.map(&:id))
+        .select(
+          "topics.*, category_featured_topics.category_id AS category_featured_topic_category_id",
+        )
+        .includes(:shared_draft, :category, { topic_thumbnails: %i[optimized_image upload] })
+        .order("category_featured_topics.rank")
 
     @all_topics = @all_topics.joins(:tags).where(tags: { name: @options[:tag] }) if @options[
       :tag
@@ -103,16 +104,18 @@ class CategoryList
     end
 
     @all_topics = TopicQuery.remove_muted_tags(@all_topics, @guardian.user).includes(:last_poster)
+
+    featured_topics_by_category_id = Hash.new { |h, k| h[k] = [] }
+
     @all_topics.each do |t|
       # hint for the serializer
       t.include_last_poster = true
       t.dismissed = dismissed_topic?(t)
-      @topics_by_id[t.id] = t
+      featured_topics_by_category_id[t.category_featured_topic_category_id] << t
     end
 
-    category_featured_topics.each do |cft|
-      @topics_by_category_id[cft.category_id] ||= []
-      @topics_by_category_id[cft.category_id] << cft.topic_id
+    categories_with_descendants.each do |category|
+      category.displayable_topics = featured_topics_by_category_id[category.id]
     end
   end
 
@@ -213,23 +216,6 @@ class CategoryList
       )
       category.has_children = category.subcategories.present?
     end
-
-    if @topics_by_category_id
-      categories_with_descendants.each do |c|
-        topics_in_cat = @topics_by_category_id[c.id]
-        if topics_in_cat.present?
-          c.displayable_topics = []
-          topics_in_cat.each do |topic_id|
-            topic = @topics_by_id[topic_id]
-            if topic.present? && @guardian.can_see?(topic)
-              # topic.category is very slow under rails 4.2
-              topic.association(:category).target = c
-              c.displayable_topics << topic
-            end
-          end
-        end
-      end
-    end
   end
 
   def prune_empty
diff --git a/spec/models/category_list_spec.rb b/spec/models/category_list_spec.rb
index 5fedc0467c5..c5495f6c2b8 100644
--- a/spec/models/category_list_spec.rb
+++ b/spec/models/category_list_spec.rb
@@ -27,21 +27,21 @@ RSpec.describe CategoryList do
 
     it "doesn't show topics that you can't view" do
       public_cat = Fabricate(:category_with_definition) # public category
-      Fabricate(:topic, category: public_cat)
+      topic_in_public_cat = Fabricate(:topic, category: public_cat)
 
       private_cat = Fabricate(:category_with_definition) # private category
-      Fabricate(:topic, category: private_cat)
+      topic_in_private_cat = Fabricate(:topic, category: private_cat)
       private_cat.set_permissions(admins: :full)
       private_cat.save
 
       secret_subcat = Fabricate(:category_with_definition, parent_category_id: public_cat.id) # private subcategory
-      Fabricate(:topic, category: secret_subcat)
+      topic_in_secret_subcat = Fabricate(:topic, category: secret_subcat)
       secret_subcat.set_permissions(admins: :full)
       secret_subcat.save
 
       muted_tag = Fabricate(:tag) # muted tag
       SiteSetting.default_tags_muted = muted_tag.name
-      Fabricate(:topic, category: public_cat, tags: [muted_tag])
+      topic_in_public_cat_2 = Fabricate(:topic, category: public_cat, tags: [muted_tag])
 
       muted_tag_2 = Fabricate(:tag)
       TagUser.create!(
@@ -58,16 +58,21 @@ RSpec.describe CategoryList do
           .categories
           .find { |x| x.name == public_cat.name }
           .displayable_topics
-          .count,
-      ).to eq(3)
+          .map(&:id),
+      ).to contain_exactly(
+        topic_in_public_cat.id,
+        topic_in_secret_subcat.id,
+        topic_in_public_cat_2.id,
+      )
+
       expect(
         CategoryList
           .new(Guardian.new(admin), include_topics: true)
           .categories
           .find { |x| x.name == private_cat.name }
           .displayable_topics
-          .count,
-      ).to eq(1)
+          .map(&:id),
+      ).to contain_exactly(topic_in_private_cat.id)
 
       expect(
         CategoryList
@@ -75,8 +80,9 @@ RSpec.describe CategoryList do
           .categories
           .find { |x| x.name == public_cat.name }
           .displayable_topics
-          .count,
-      ).to eq(2)
+          .map(&:id),
+      ).to contain_exactly(topic_in_public_cat.id, topic_in_public_cat_2.id)
+
       expect(
         CategoryList
           .new(Guardian.new(user), include_topics: true)
@@ -90,8 +96,9 @@ RSpec.describe CategoryList do
           .categories
           .find { |x| x.name == public_cat.name }
           .displayable_topics
-          .count,
-      ).to eq(1)
+          .map(&:id),
+      ).to contain_exactly(topic_in_public_cat.id)
+
       expect(
         CategoryList
           .new(Guardian.new(nil), include_topics: true)
@@ -112,8 +119,8 @@ RSpec.describe CategoryList do
           .categories
           .find { |x| x.name == cat.name }
           .displayable_topics
-          .count,
-      ).to eq(1)
+          .map(&:id),
+      ).to contain_exactly(topic.id)
 
       TopicUser.change(user.id, topic.id, notification_level: TopicUser.notification_levels[:muted])