diff --git a/lib/amazing_print/ext/active_record.rb b/lib/amazing_print/ext/active_record.rb
index 082a187..67762b5 100644
--- a/lib/amazing_print/ext/active_record.rb
+++ b/lib/amazing_print/ext/active_record.rb
@@ -22,9 +22,9 @@ def cast_with_active_record(object, type)
         cast = :active_record_instance
       elsif object.is_a?(::ActiveModel::Errors)
         cast = :active_model_error
-      elsif object.is_a?(Class) && object.ancestors.include?(::ActiveRecord::Base)
+      elsif object.is_a?(Class) && object <= ::ActiveRecord::Base
         cast = :active_record_class
-      elsif type == :activerecord_relation || object.class.ancestors.include?(::ActiveRecord::Relation)
+      elsif type == :activerecord_relation || object.is_a?(::ActiveRecord::Relation)
         cast = :array
       end
       cast