diff --git a/app/controllers/overview_controller.rb b/app/controllers/overview_controller.rb
index 8e78cd25..28dc4c6c 100644
--- a/app/controllers/overview_controller.rb
+++ b/app/controllers/overview_controller.rb
@@ -37,6 +37,6 @@ class OverviewController < SqmApplicationController
   end
 
   def categories
-    @categories ||= Category.sorted.includes(%i[measures admin_data_items subcategories])
+    @categories ||= Category.sorted.includes(%i[measures scales admin_data_items subcategories])
   end
 end
diff --git a/app/models/category.rb b/app/models/category.rb
index 318d3f5f..ad546a98 100644
--- a/app/models/category.rb
+++ b/app/models/category.rb
@@ -9,4 +9,5 @@ class Category < ActiveRecord::Base
   has_many :subcategories
   has_many :measures, through: :subcategories
   has_many :admin_data_items, through: :measures
+  has_many :scales, through: :subcategories
 end