diff --git a/lisp/ring-list/ring-list.lisp b/lisp/ring-list/ring-list.lisp
index c1a14a2..4c32767 100644
--- a/lisp/ring-list/ring-list.lisp
+++ b/lisp/ring-list/ring-list.lisp
@@ -3,6 +3,7 @@
   (:export
    #:make-ring-list
    #:ring-list
+   #:ring-list-size
    #:add-item
    #:remove-item
    #:pop-item