diff --git a/Kernel_23/include/CGAL/Kernel/function_objects.h b/Kernel_23/include/CGAL/Kernel/function_objects.h
index 1a7065e1a59..f8f5817c522 100644
--- a/Kernel_23/include/CGAL/Kernel/function_objects.h
+++ b/Kernel_23/include/CGAL/Kernel/function_objects.h
@@ -31,7 +31,6 @@
 #include <CGAL/Kernel/Return_base_tag.h>
 #include <CGAL/Kernel/global_functions_3.h>
 
-#include <type_traits> // for std::is_same and std::enable_if
 #include <cmath> // for Compute_dihedral_angle
 
 namespace CGAL {