diff --git a/activerecord/lib/active_record/attribute_assignment.rb b/activerecord/lib/active_record/attribute_assignment.rb
index 8b0d9aab01..23a980318c 100644
--- a/activerecord/lib/active_record/attribute_assignment.rb
+++ b/activerecord/lib/active_record/attribute_assignment.rb
@@ -4,7 +4,6 @@ require "active_model/forbidden_attributes_protection"
 
 module ActiveRecord
   module AttributeAssignment
-    extend ActiveSupport::Concern
     include ActiveModel::AttributeAssignment
 
     # Alias for ActiveModel::AttributeAssignment#assign_attributes. See ActiveModel::AttributeAssignment.