diff --git a/activerecord/test/cases/associations/eager_load_nested_include_test.rb b/activerecord/test/cases/associations/eager_load_nested_include_test.rb
index c7671a8c22a3b..8957586189de0 100644
--- a/activerecord/test/cases/associations/eager_load_nested_include_test.rb
+++ b/activerecord/test/cases/associations/eager_load_nested_include_test.rb
@@ -4,6 +4,7 @@
 require 'models/comment'
 require 'models/category'
 require 'models/categorization'
+require 'models/tagging'
 require 'active_support/core_ext/array/random_access'
 
 module Remembered