diff --git a/test/drb/ut_drb.rb b/test/drb/ut_drb.rb
index b1306d0cb0..f05d3f8e1f 100644
--- a/test/drb/ut_drb.rb
+++ b/test/drb/ut_drb.rb
@@ -69,7 +69,7 @@ class DRbEx
     private def priv; 3; end
   end
   def basic_object
-    BO.new
+    @basic_object = BO.new
   end
 
   def unknown_class