1 files changed, 1 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb b/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
index 6c2b9b89fd..6d0704db74 100644
--- a/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
+++ b/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb
@@ -9,7 +9,7 @@ module ActiveRecord
 
           unless record.new_record?
             @owner[@reflection.primary_key_name] = record.id
-            @owner[@reflection.options[:foreign_type]] = ActiveRecord::Base.send(:class_name_of_active_record_descendant, record.class).to_s
+            @owner[@reflection.options[:foreign_type]] = record.class.base_class.name.to_s
           end
 
           @updated = true