diff --git a/Triangulation_2/examples/Triangulation_2/constrained.cpp b/Triangulation_2/examples/Triangulation_2/constrained.cpp
index 84ff46a8155..9901ec05fd3 100644
--- a/Triangulation_2/examples/Triangulation_2/constrained.cpp
+++ b/Triangulation_2/examples/Triangulation_2/constrained.cpp
@@ -22,7 +22,7 @@ main( )
 
   assert(cdt.is_valid());
   int count = 0;
-  for (Edge e : cdt.finite_edges())
+  for (const Edge& e : cdt.finite_edges())
     if (cdt.is_constrained(e))
       ++count;
   std::cout << "The number of resulting constrained edges is  ";
diff --git a/Triangulation_2/examples/Triangulation_2/polylines_triangulation.cpp b/Triangulation_2/examples/Triangulation_2/polylines_triangulation.cpp
index 623194cbf8e..60ab20dd663 100644
--- a/Triangulation_2/examples/Triangulation_2/polylines_triangulation.cpp
+++ b/Triangulation_2/examples/Triangulation_2/polylines_triangulation.cpp
@@ -34,7 +34,7 @@ contexts(const CDTP& cdtp)
     if(cdtp.number_of_enclosing_constraints(vp, vq) == 2){
       std::cout << "subconstraint " << vp->point() << " " << vq->point() 
                 << " is on constraints starting at:\n";
-      for(CDTP::Context c : cdtp.contexts(vp,vq)){
+      for(const CDTP::Context& c : cdtp.contexts(vp,vq)){
         std::cout << (*(c.vertices_begin()))->point() << std::endl;
       }
     }