diff --git a/include/boost/geometry/formulas/karney_direct.hpp b/include/boost/geometry/formulas/karney_direct.hpp
index 38460fb1e..8e81cf459 100644
--- a/include/boost/geometry/formulas/karney_direct.hpp
+++ b/include/boost/geometry/formulas/karney_direct.hpp
@@ -11,6 +11,7 @@
 
 
 #include <boost/math/constants/constants.hpp>
+#include <boost/math/special_functions/hypot.hpp>
 
 #include <boost/geometry/util/math.hpp>
 #include <boost/geometry/util/series_expansion.hpp>
diff --git a/include/boost/geometry/util/series_expansion.hpp b/include/boost/geometry/util/series_expansion.hpp
index cca43284c..f7e4595da 100644
--- a/include/boost/geometry/util/series_expansion.hpp
+++ b/include/boost/geometry/util/series_expansion.hpp
@@ -538,7 +538,7 @@ namespace boost { namespace geometry { namespace series_expansion {
                s/eps(CT(2))/eps2/g;'
     */
     template <typename CT, std::size_t SeriesOrder>
-    static inline evaluate_coeffs_C1p(CT eps, CT c[])
+    static inline void evaluate_coeffs_C1p(CT eps, CT c[])
     {
         CT const eps2 = math::sqr(eps);
         CT d = eps;