diff --git a/lib/acts_as_list/active_record/acts/scope_method_definer.rb b/lib/acts_as_list/active_record/acts/scope_method_definer.rb
index 204fc4ae..9da0656a 100644
--- a/lib/acts_as_list/active_record/acts/scope_method_definer.rb
+++ b/lib/acts_as_list/active_record/acts/scope_method_definer.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+require "active_support/inflector"
 
 module ActiveRecord::Acts::List::ScopeMethodDefiner #:nodoc:
   extend ActiveSupport::Inflector