diff --git a/GraphicsView/demo/Triangulation_2/Constrained_Delaunay_triangulation_2.cpp b/GraphicsView/demo/Triangulation_2/Constrained_Delaunay_triangulation_2.cpp
index 1844916dd25..926140d9661 100644
--- a/GraphicsView/demo/Triangulation_2/Constrained_Delaunay_triangulation_2.cpp
+++ b/GraphicsView/demo/Triangulation_2/Constrained_Delaunay_triangulation_2.cpp
@@ -66,6 +66,7 @@ typedef CDT::Vertex_handle Vertex_handle;
 typedef CDT::Face_handle Face_handle;
 typedef CDT::All_faces_iterator All_faces_iterator;
 
+using namespace parameters;
 
 void
 discoverInfiniteComponent(const CDT & ct)