diff --git a/Straight_skeleton_2/test/Straight_skeleton_2/print.h b/Straight_skeleton_2/test/Straight_skeleton_2/print.h
index 62d370a4f6b..abaa74d9e46 100644
--- a/Straight_skeleton_2/test/Straight_skeleton_2/print.h
+++ b/Straight_skeleton_2/test/Straight_skeleton_2/print.h
@@ -1,7 +1,7 @@
-#include <CGAL/Point_2>
-#include <CGAL/Polygon_2>
-#include <CGAL/Polygon_with_holes_2>
-#include <CGAL/Straight_skeleton_2>
+#include <CGAL/Point_2.h>
+#include <CGAL/Polygon_2.h>
+#include <CGAL/Polygon_with_holes_2.h>
+#include <CGAL/Straight_skeleton_2.h>
 
 template<class K>
 void print_point ( CGAL::Point_2<K> const& p )