diff --git a/src/csg/cgal_helper_polygon.cpp b/src/csg/cgal_helper_polygon.cpp
index 2b95b9d9b977d3206bc4e0c26f48d04aca25a0fc..36a214308c1bb61e6cef7f71047a7a9d4c709598 100644
--- a/src/csg/cgal_helper_polygon.cpp
+++ b/src/csg/cgal_helper_polygon.cpp
@@ -1,11 +1,7 @@
 #include "csg_cgal_helper.hpp"
 
-#include <CGAL/Polygon_2.h>
-#include <CGAL/Polygon_2_algorithms.h>
-
 namespace {
-typedef CGAL::Polygon_2<cgal_helper::IK> Polygon;
-typedef CGAL::Point_2<cgal_helper::IK> Point;
+typedef CGAL::Point_2<cgal_helper::CK> Point;
 } // namespace
 
 namespace cgal_helper {
@@ -32,8 +28,7 @@ Polygon create_polygon(const std::vector<std::tuple<double, double>> &points,
 
 bool inside(const Polygon &polygon, double xx, double yy) {
 
-  return CGAL::bounded_side_2(polygon.begin(), polygon.end(), Point(xx, yy),
-                              IK()) == CGAL::ON_BOUNDED_SIDE;
+  return polygon.has_on_bounded_side(Point(xx, yy));
 }
 
 } // namespace cgal_helper
diff --git a/src/csg_cgal_helper.hpp b/src/csg_cgal_helper.hpp
index 0326d23b8b50363efaac97ab3733d79595c8072e..f4cc6883e3632696a0880956da95ed7c1352a38f 100644
--- a/src/csg_cgal_helper.hpp
+++ b/src/csg_cgal_helper.hpp
@@ -10,8 +10,7 @@ namespace cgal_helper {
 
 typedef CGAL::Simple_cartesian<double> CK;
 typedef CGAL::Polyhedron_3<CK> Polyhedron;
-typedef CGAL::Exact_predicates_inexact_constructions_kernel IK;
-typedef CGAL::Polygon_2<IK> Polygon;
+typedef CGAL::Polygon_2<CK> Polygon;
 
 Polyhedron
 create_polyhedron(const std::vector<std::tuple<double, double, double>> &points,