diff --git a/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_offset.cpp b/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_offset.cpp
index b505f6de606..7259dd75e96 100644
--- a/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_offset.cpp
+++ b/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_offset.cpp
@@ -22,10 +22,13 @@
 #include <CGAL/Straight_skeleton_2/IO/print.h>
 #include <CGAL/Timer.h>
 
-#include <memory>
+#include <CGAL/use.h>
+
+#include <boost/shared_ptr.hpp>
 
 #include <cassert>
 #include <iostream>
+#include <memory>
 #include <string>
 #include <vector>
 
@@ -1128,6 +1131,7 @@ void test_kernel()
   std::cerr.precision(17);
 
   void (*dummy_ptr)() = &test_API<K>;
+  CGAL_USE(dummy_ptr);
 
   // Artificial data
   test_offset_square<K>();
diff --git a/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_simple.cpp b/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_simple.cpp
index 748187c6528..4f5ad621567 100644
--- a/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_simple.cpp
+++ b/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_simple.cpp
@@ -34,10 +34,13 @@ void Straight_skeleton_traits_external_trace(std::string m)
 #include <CGAL/Polygon_2.h>
 #include <CGAL/draw_polygon_2.h>
 
-#include <memory>
+#include <CGAL/use.h>
+
+#include <boost/shared_ptr.hpp>
 
 #include <cassert>
 #include <iostream>
+#include <memory>
 #include <set>
 #include <string>
 #include <vector>
@@ -222,6 +225,7 @@ void test_kernel()
 //  CGAL_STSKEL_TRAITS_ENABLE_TRACE
 
   void (*dummy_ptr)() = &test_API<K>;
+  CGAL_USE(dummy_ptr);
 
   test_skeleton<K>("data/pseudo_split_0.poly", 13, 40, 8);
   test_skeleton<K>("data/pseudo_split_1.poly", 21, 68, 12);
diff --git a/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_offset.cpp b/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_offset.cpp
index 6e04f2899e8..e4e64c2c95b 100644
--- a/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_offset.cpp
+++ b/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_offset.cpp
@@ -12,6 +12,8 @@
 #include <CGAL/Polygon_with_holes_2.h>
 #include <CGAL/Straight_skeleton_2/IO/print.h>
 
+#include <CGAL/use.h>
+
 #include <boost/shared_ptr.hpp>
 
 #include <cassert>
@@ -271,6 +273,7 @@ template <typename K>
 void test_kernel()
 {
   void (*dummy_ptr)() = &test_API<K>;
+  CGAL_USE(dummy_ptr);
 }
 
 int main(int, char**)
diff --git a/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_polygons.cpp b/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_polygons.cpp
index f6bedc49ab6..54a3be0ad86 100644
--- a/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_polygons.cpp
+++ b/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_polygons.cpp
@@ -18,6 +18,8 @@
 #include <CGAL/create_weighted_offset_polygons_2.h>
 #include <CGAL/extrude_skeleton.h>
 
+#include <CGAL/use.h>
+
 #include <boost/shared_ptr.hpp>
 
 #include <iostream>
@@ -62,7 +64,6 @@ void test_kernel(const int polygon_nv, CGAL::Random& rnd)
 {
   using FT = typename K::FT;
   using Point_2 = typename  K::Point_2;
-  using Vector_2 = typename  K::Vector_2;
   using Point_3 = typename K::Point_3;
 
   using Polygon_2 = CGAL::Polygon_2<K>;
@@ -73,6 +74,7 @@ void test_kernel(const int polygon_nv, CGAL::Random& rnd)
   using Mesh = CGAL::Surface_mesh<Point_3>;
 
   void (*dummy_ptr)() = &test_API<K>;
+  CGAL_USE(dummy_ptr);
 
   typedef CGAL::Random_points_in_square_2<Point_2> Point_generator;
   Polygon_2 pol;
@@ -92,7 +94,7 @@ void test_kernel(const int polygon_nv, CGAL::Random& rnd)
 
   CGAL::draw(pol);
 
-  auto ss_ptr = CGAL::create_interior_weighted_straight_skeleton_2(pol, weights);
+  Straight_skeleton_2_ptr ss_ptr = CGAL::create_interior_weighted_straight_skeleton_2(pol, weights, K());
   assert(ss_ptr);
   if(!ss_ptr)
   {
@@ -102,7 +104,7 @@ void test_kernel(const int polygon_nv, CGAL::Random& rnd)
 
   CGAL::draw(*ss_ptr);
 
-  ss_ptr = CGAL::create_exterior_weighted_straight_skeleton_2(0.1, pol, weights);
+  ss_ptr = CGAL::create_exterior_weighted_straight_skeleton_2(0.1, pol, weights, K());
   assert(ss_ptr);
   if(!ss_ptr)
   {
diff --git a/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_polygons_with_holes.cpp b/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_polygons_with_holes.cpp
index 975435df3ff..7c5308ea205 100644
--- a/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_polygons_with_holes.cpp
+++ b/Straight_skeleton_2/test/Straight_skeleton_2/test_sls_weighted_polygons_with_holes.cpp
@@ -48,7 +48,7 @@ void test_kernel(const int hole_n, const int hole_nv, CGAL::Random& rnd)
     typedef CGAL::Random_points_in_square_2<Point_2> Point_generator;
 
     Polygon_2 poly;
-    CGAL::random_polygon_2(10, std::back_inserter(poly), Point_generator(0.25, rnd));
+    CGAL::random_polygon_2(hole_nv, std::back_inserter(poly), Point_generator(0.25, rnd));
     return poly;
   };
 
@@ -113,7 +113,7 @@ void test_kernel(const int hole_n, const int hole_nv, CGAL::Random& rnd)
 
 //  CGAL::draw(pwh);
 
-  auto ss_ptr = CGAL::create_interior_weighted_straight_skeleton_2(pwh, weights);
+  Straight_skeleton_2_ptr ss_ptr = CGAL::create_interior_weighted_straight_skeleton_2(pwh, weights, K());
   assert(ss_ptr);
   if(!ss_ptr)
   {