diff --git a/activesupport/lib/active_support/core_ext/marshal.rb b/activesupport/lib/active_support/core_ext/marshal.rb
index 0c72cd7b470b5590b9f79da3d87bcc23b934be18..5ff0e34d8245bccb9c34add0c71cb14628320d63 100644
--- a/activesupport/lib/active_support/core_ext/marshal.rb
+++ b/activesupport/lib/active_support/core_ext/marshal.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "active_support/core_ext/string/inflections"
+
 module ActiveSupport
   module MarshalWithAutoloading # :nodoc:
     def load(source, proc = nil)