diff --git a/Circular_kernel_3/include/CGAL/Circular_kernel_3/internal_function_has_on_spherical_kernel.h b/Circular_kernel_3/include/CGAL/Circular_kernel_3/internal_function_has_on_spherical_kernel.h
index 002f00687be..66a8e84793c 100644
--- a/Circular_kernel_3/include/CGAL/Circular_kernel_3/internal_function_has_on_spherical_kernel.h
+++ b/Circular_kernel_3/include/CGAL/Circular_kernel_3/internal_function_has_on_spherical_kernel.h
@@ -25,6 +25,8 @@
 #ifndef CGAL_SPHERICAL_KERNEL_PREDICATES_HAS_ON_3_H
 #define CGAL_SPHERICAL_KERNEL_PREDICATES_HAS_ON_3_H
 
+#include <CGAL/Circular_kernel_3/internal_functions_on_sphere_3.h>
+
 namespace CGAL {
   namespace SphericalFunctors {
 
diff --git a/Circular_kernel_3/include/CGAL/global_functions_spherical_kernel_3.h b/Circular_kernel_3/include/CGAL/global_functions_spherical_kernel_3.h
index 7174528f2c6..6045e0171a5 100644
--- a/Circular_kernel_3/include/CGAL/global_functions_spherical_kernel_3.h
+++ b/Circular_kernel_3/include/CGAL/global_functions_spherical_kernel_3.h
@@ -46,6 +46,9 @@ class Circle_3;
 template <class SK>
 class Sphere_3;
 
+template <class K>
+class Vector_3;
+
 template <class SK>
 Circular_arc_point_3<SK>
 x_extremal_point(const Circle_3<SK> & c, bool i)