diff --git a/lemon/concepts/digraph.h b/lemon/concepts/digraph.h
--- a/lemon/concepts/digraph.h
+++ b/lemon/concepts/digraph.h
@@ -23,8 +23,7 @@
 ///\file
 ///\brief The concept of directed graphs.
 
-#include <lemon/bits/invalid.h>
-#include <lemon/bits/utility.h>
+#include <lemon/core.h>
 #include <lemon/concepts/maps.h>
 #include <lemon/concept_check.h>
 #include <lemon/concepts/graph_components.h>