diff --git a/include/hpp/manipulation/graph/edge.hh b/include/hpp/manipulation/graph/edge.hh
index 9a25a670a776dfe1c9b9ddc96dbc9af136d1e5f3..e4bb54ac65e618f3a5f33dd970fe6c77378b5cea 100644
--- a/include/hpp/manipulation/graph/edge.hh
+++ b/include/hpp/manipulation/graph/edge.hh
@@ -29,6 +29,7 @@
 namespace hpp {
   namespace manipulation {
     namespace graph {
+      /// \cond
       /// Cache mechanism that enable const-correctness of member functions.
       template <typename C>
         class HPP_MANIPULATION_LOCAL Cache
@@ -52,6 +53,7 @@ namespace hpp {
         private:
           C c_;
       };
+      /// \endcond
 
       /// \addtogroup constraint_graph
       /// \{