diff --git a/app/models/project_category.rb b/app/models/project_category.rb
index 6da12560d..256b0cd1b 100644
--- a/app/models/project_category.rb
+++ b/app/models/project_category.rb
@@ -1,2 +1,3 @@
 class ProjectCategory < ApplicationRecord
+  has_ancestry
 end
diff --git a/db/migrate/20191218021144_add_ancestry_to_project_categories.rb b/db/migrate/20191218021144_add_ancestry_to_project_categories.rb
new file mode 100644
index 000000000..e08606ee9
--- /dev/null
+++ b/db/migrate/20191218021144_add_ancestry_to_project_categories.rb
@@ -0,0 +1,6 @@
+class AddAncestryToProjectCategories < ActiveRecord::Migration[5.2]
+  def change
+    add_column :project_categories, :ancestry, :string
+    add_index :project_categories, :ancestry
+  end
+end