diff --git a/collects/hierlist/hierlist-sig.ss b/collects/hierlist/hierlist-sig.ss
index d6041dde..4542c737 100644
--- a/collects/hierlist/hierlist-sig.ss
+++ b/collects/hierlist/hierlist-sig.ss
@@ -8,6 +8,9 @@
      hierarchical-list-item<%>
      hierarchical-list-item%
      hierarchical-list-compound-item<%>
-     hierarchical-list-compound-item%)))
+     hierarchical-list-compound-item%
+     
+     hierarchical-item-snip%
+     hierarchical-list-snip%)))