diff --git a/trees/cb/cb.factor b/trees/cb/cb.factor
index bde3e36..fda8fc3 100644
--- a/trees/cb/cb.factor
+++ b/trees/cb/cb.factor
@@ -240,6 +240,8 @@ M: cb new-assoc
 
 GENERIC: (cb-node>alist) ( node -- )
 
+M: object (cb-node>alist) drop ;
+
 M: node (cb-node>alist)
     entry, ;