diff --git a/Triangulation_2/include/CGAL/Constrained_triangulation_plus_2.h b/Triangulation_2/include/CGAL/Constrained_triangulation_plus_2.h
index 3cca4fe27a0..690a9486fb2 100644
--- a/Triangulation_2/include/CGAL/Constrained_triangulation_plus_2.h
+++ b/Triangulation_2/include/CGAL/Constrained_triangulation_plus_2.h
@@ -341,10 +341,14 @@ inline void
 Constrained_triangulation_plus_2<Tr>::
 insert_constraint(Vertex_handle va, Vertex_handle vb)
 {
-  // protects against inserting twice the same constraint
-  bool no_twice = hierarchy.insert_constraint(va, vb);
-  if (va != vb && no_twice )  insert_subconstraint(va,vb); 
-  return;
+  if( va != vb ){
+    // protects against inserting twice the same constraint
+    bool no_twice = hierarchy.insert_constraint(va, vb);
+    if ( no_twice ){
+      insert_subconstraint(va,vb);
+    } 
+  }
+    return;
 }