diff --git a/Triangulation_2/include/CGAL/Constrained_Delaunay_triangulation_2.h b/Triangulation_2/include/CGAL/Constrained_Delaunay_triangulation_2.h
index 35c8a43ec6f..3ede97507be 100644
--- a/Triangulation_2/include/CGAL/Constrained_Delaunay_triangulation_2.h
+++ b/Triangulation_2/include/CGAL/Constrained_Delaunay_triangulation_2.h
@@ -445,10 +445,9 @@ public:
 
   template <class PointIterator, class IndicesIterator>
   std::size_t insert_unique_constraints(PointIterator points_first,
-                                 PointIterator points_beyond,
-                                 IndicesIterator indices_first,
-                                 IndicesIterator indices_beyond,
-                                 bool check_duplicates = false)
+                                        PointIterator points_beyond,
+                                        IndicesIterator indices_first,
+                                        IndicesIterator indices_beyond)
   {
     std::vector<Point> points(points_first, points_beyond);
     return internal::insert_constraints(*this, points, indices_first, indices_beyond, true);
@@ -457,8 +456,7 @@ public:
 
   template <class ConstraintIterator>
   std::size_t insert_unique_constraints(ConstraintIterator first,
-                                 ConstraintIterator beyond,
-                                 bool check_duplicates = false)
+                                        ConstraintIterator beyond)
   {
     return internal::insert_constraints(*this, first, beyond, true);
   }