diff --git a/concept_checking.html b/concept_checking.html
index 227f322..0c1a15f 100644
--- a/concept_checking.html
+++ b/concept_checking.html
@@ -117,8 +117,8 @@ checker.
 <P>
 Here's a quick example program that one could write to see if the
 types <a
-href="../graph/adjacency_list.html"><TT>adjacency_list</TT></a> and <a
-href="../graph/edge_list.html"><TT>edge_list</TT></a> really model the
+href="../graph/docs/adjacency_list.html"><TT>adjacency_list</TT></a> and <a
+href="../graph/docs/edge_list.html"><TT>edge_list</TT></a> really model the
 concepts they claim to.
 
 <P>