diff --git a/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/Curve_renderer_facade.h b/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/Curve_renderer_facade.h
index fa9edb87341..0864d41e566 100644
--- a/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/Curve_renderer_facade.h
+++ b/Curved_kernel_via_analysis_2/include/CGAL/Curved_kernel_via_analysis_2/Curve_renderer_facade.h
@@ -25,9 +25,9 @@
 //#define CGAL_CKVA_DUMMY_RENDERER
 
 // whether to use multi-precision arithmetic
-//#define CGAL_CKVA_USE_MULTIPREC_ARITHMETIC
+#define CGAL_CKVA_USE_MULTIPREC_ARITHMETIC
 // whether to use exact rational arithmetic
-//#define CGAL_CKVA_USE_RATIONAL_ARITHMETIC
+#define CGAL_CKVA_USE_RATIONAL_ARITHMETIC
 
 // this turns on a signleton curve renderer 
 // (not recommended for multi-threaded applications)