diff --git a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/intersection.h b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/intersection.h
index a72d9ffaafc..a996edae648 100644
--- a/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/intersection.h
+++ b/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/intersection.h
@@ -1428,12 +1428,12 @@ bool do_intersect(const TriangleMesh& tm,
 #ifndef DOXYGEN_RUNNING
                 , const std::enable_if_t<!(
                       std::is_same_v<TriangleMesh, Polyline> || // Added to please MSVC 2015
-                      !boost::has_range_iterator<Polyline>::type>::value || // not a range
+                      !boost::has_range_iterator<Polyline>::value || // not a range
                       boost::has_range_iterator<
                         typename boost::mpl::eval_if<
                           boost::has_range_iterator<Polyline>,
                           boost::range_value<Polyline>,
-                          std::false_type
+                          std::false_type>::type
                         >::value
                     )
                   >* = 0
diff --git a/QP_solver/test/QP_solver/test_solver.cpp b/QP_solver/test/QP_solver/test_solver.cpp
index ad298449b55..4fc641cc286 100644
--- a/QP_solver/test/QP_solver/test_solver.cpp
+++ b/QP_solver/test/QP_solver/test_solver.cpp
@@ -282,6 +282,7 @@ bool process(const std::string& filename,
 {
   using std::cout;
   using std::endl;
+  using CGAL::check_tag;
 
   // extract verbosity:
   const int verbosity = options.find("Verbosity")->second;
diff --git a/Triangulation_3/include/CGAL/Regular_triangulation_3.h b/Triangulation_3/include/CGAL/Regular_triangulation_3.h
index b4ff7de189c..18026962520 100644
--- a/Triangulation_3/include/CGAL/Regular_triangulation_3.h
+++ b/Triangulation_3/include/CGAL/Regular_triangulation_3.h
@@ -612,8 +612,8 @@ public:
   insert(boost::zip_iterator< boost::tuple<InputIterator_1,InputIterator_2> > first,
          boost::zip_iterator< boost::tuple<InputIterator_1,InputIterator_2> > last,
          std::enable_if_t<
-           typename std::is_convertible_v< typename std::iterator_traits<InputIterator_1>::value_type, Weighted_point > &&
-           typename std::is_convertible_v< typename std::iterator_traits<InputIterator_2>::value_type, typename internal::Info_check<typename Triangulation_data_structure::Vertex>::type >
+           std::is_convertible_v< typename std::iterator_traits<InputIterator_1>::value_type, Weighted_point > &&
+           std::is_convertible_v< typename std::iterator_traits<InputIterator_2>::value_type, typename internal::Info_check<typename Triangulation_data_structure::Vertex>::type >
          >* =nullptr)
   {
     return insert_with_info<