diff --git a/activesupport/test/core_ext/string_ext_test.rb b/activesupport/test/core_ext/string_ext_test.rb
index bb865cae91..9371965bbd 100644
--- a/activesupport/test/core_ext/string_ext_test.rb
+++ b/activesupport/test/core_ext/string_ext_test.rb
@@ -3,6 +3,7 @@ require 'date'
 require 'abstract_unit'
 require 'inflector_test_cases'
 
+require 'active_support/inflector'
 require 'active_support/core_ext/string'
 require 'active_support/time'
 require 'active_support/core_ext/kernel/reporting'