diff --git a/alsalisp/hctl.lisp b/alsalisp/hctl.lisp
index 488d71f2..504050f6 100644
--- a/alsalisp/hctl.lisp
+++ b/alsalisp/hctl.lisp
@@ -67,6 +67,7 @@
 	    (setq elem (Acall 'hctl_elem_next elem))
 	  )
         )
+	(unsetq elem)
         (setq hctl (Acall 'hctl_close hctl))
         (if (= hctl 0)
           (princ "hctl close success\n")