diff --git a/Spatial_sorting/include/CGAL/Hilbert_sort_median_2.h b/Spatial_sorting/include/CGAL/Hilbert_sort_median_2.h
index 3d389481e97..23e87f7ac7b 100644
--- a/Spatial_sorting/include/CGAL/Hilbert_sort_median_2.h
+++ b/Spatial_sorting/include/CGAL/Hilbert_sort_median_2.h
@@ -139,7 +139,9 @@ public:
     RandomAccessIterator begin, end;
     const Comp& comp;
 
-    Hilbert_split(RandomAccessIterator& res, RandomAccessIterator begin, RandomAccessIterator end, const Comp comp)
+    Hilbert_split(RandomAccessIterator& res,
+                  RandomAccessIterator begin, RandomAccessIterator end,
+                  const Comp& comp)
       : res(res), begin(begin), end(end), comp(comp)
     {}
 
diff --git a/Spatial_sorting/include/CGAL/Hilbert_sort_median_3.h b/Spatial_sorting/include/CGAL/Hilbert_sort_median_3.h
index 0536ef8be94..0ea51bb24bc 100644
--- a/Spatial_sorting/include/CGAL/Hilbert_sort_median_3.h
+++ b/Spatial_sorting/include/CGAL/Hilbert_sort_median_3.h
@@ -156,7 +156,9 @@ public:
     RandomAccessIterator begin, end;
     const Comp& comp;
 
-    Hilbert_split(RandomAccessIterator& res, RandomAccessIterator begin, RandomAccessIterator end, const Comp comp)
+    Hilbert_split(RandomAccessIterator& res,
+                  RandomAccessIterator begin, RandomAccessIterator end,
+                  const Comp& comp)
       : res(res), begin(begin), end(end), comp(comp)
     {}