diff --git a/Cone_spanners_2/test/Cone_spanners_2/theta_exact.cpp b/Cone_spanners_2/test/Cone_spanners_2/theta_exact.cpp
index 88f1d31c8a9..5f70e312557 100644
--- a/Cone_spanners_2/test/Cone_spanners_2/theta_exact.cpp
+++ b/Cone_spanners_2/test/Cone_spanners_2/theta_exact.cpp
@@ -22,7 +22,11 @@ typedef Kernel::Direction_2               Direction_2;
 // define the graph type
 typedef boost::adjacency_list<boost::listS,
                               boost::vecS,
+                              #ifdef CGAL_CXX11
+                              boost::undirectedS,
+                              #else
                               boost::directedS,
+                              #endif
                               Point_2
                              > Graph;