diff --git a/Mesh_2/include/CGAL/Mesh_2/Mesh_global_optimizer_2.h b/Mesh_2/include/CGAL/Mesh_2/Mesh_global_optimizer_2.h
index 380696549c13..d2df50df3fa7 100644
--- a/Mesh_2/include/CGAL/Mesh_2/Mesh_global_optimizer_2.h
+++ b/Mesh_2/include/CGAL/Mesh_2/Mesh_global_optimizer_2.h
@@ -29,6 +29,7 @@
 #include <CGAL/Constrained_voronoi_diagram_2.h>
 
 #include <vector>
+#include <set>
 #include <list>
 #include <algorithm>
 #include <iterator>
diff --git a/Surface_sweep_2/include/CGAL/Surface_sweep_2/Surface_sweep_2_impl.h b/Surface_sweep_2/include/CGAL/Surface_sweep_2/Surface_sweep_2_impl.h
index eafd4d73b895..21b21d10fb9c 100644
--- a/Surface_sweep_2/include/CGAL/Surface_sweep_2/Surface_sweep_2_impl.h
+++ b/Surface_sweep_2/include/CGAL/Surface_sweep_2/Surface_sweep_2_impl.h
@@ -15,6 +15,8 @@
 #define CGAL_SURFACE_SWEEP_2_IMPL_H
 
 #include <CGAL/license/Surface_sweep_2.h>
+#include <set>
+#include <vector>
 
 /*! \file
  *