diff --git a/gtsam/base/numericalDerivative.h b/gtsam/base/numericalDerivative.h
index fb6f75fba..ded96a520 100644
--- a/gtsam/base/numericalDerivative.h
+++ b/gtsam/base/numericalDerivative.h
@@ -466,9 +466,9 @@ namespace gtsam {
    */
 	template<class X>
 	inline Matrix numericalHessian(boost::function<double(const X&)> f, const X& x, double delta=1e-5) {
-	  Vector (*numGrad)(boost::function<double(const X&)>,const X&, double) = &numericalGradient<X>;
 	  return numericalDerivative11<X>(boost::function<Vector(const X&)>(boost::bind(
-	          numGrad, f, _1, delta)), x, delta);
+	      static_cast<Vector (*)(boost::function<double(const X&)>,const X&, double)>(&numericalGradient<X>),
+	      f, _1, delta)), x, delta);
 	}
 
 	template<class X>