diff --git a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/refine_zero_against.h b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/refine_zero_against.h
index 962764f6111..dc3fbd5d318 100644
--- a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/refine_zero_against.h
+++ b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/refine_zero_against.h
@@ -20,12 +20,6 @@
 #include <CGAL/basic.h>
 
 #include <CGAL/Polynomial.h>
-/*#include <NiX/Modular.h>
-#include <NiX/bezout_matrix.h>
-#include <NiX/determinant.h>
-#include <NiX/number_type_utils.h>
-#include <NiX/filter_tools.h>
-#include <NiX/polynomial_utils.h>*/
 
 CGAL_BEGIN_NAMESPACE