diff --git a/unsupported/Eigen/src/NonLinear/MathFunctions.h b/unsupported/Eigen/src/NonLinear/MathFunctions.h
index 31d803b8c..b2c696b3f 100644
--- a/unsupported/Eigen/src/NonLinear/MathFunctions.h
+++ b/unsupported/Eigen/src/NonLinear/MathFunctions.h
@@ -27,22 +27,19 @@
 
 #include <cminpack.h>
 
-template<typename Functor, typename VectorType>
+template<typename Functor, typename Scalar>
 // TODO : fixe Scalar here
 int ei_hybrd1(
-        VectorType &x,
-        VectorType &fvec,
-//        ei_traits<VectorType>::Scalar tol
-        double  tol
-//        = ei_sqrt(machine_epsilon<VectorType::Scalar>())
+        Eigen::Matrix< double, Eigen::Dynamic, 1 >  &x,
+        Eigen::Matrix< double, Eigen::Dynamic, 1 >  &fvec,
+        Scalar tol = Eigen::ei_sqrt(Eigen::machine_epsilon<Scalar>())
         )
 {
-    typedef typename VectorType::Scalar Scalar;
     int lwa = (x.size()*(3*x.size()+13))/2;
-    VectorType wa(lwa);
+    Eigen::Matrix< double, Eigen::Dynamic, 1 > wa(lwa);
     fvec.resize(x.size());
     return hybrd1(Functor::f, 0, x.size(), x.data(), fvec.data(), tol, wa.data(), lwa);
 }
 
-
 #endif // EIGEN_NONLINEAR_MATHFUNCTIONS_H
+
diff --git a/unsupported/test/NonLinear.cpp b/unsupported/test/NonLinear.cpp
index d877ba375..18766757e 100644
--- a/unsupported/test/NonLinear.cpp
+++ b/unsupported/test/NonLinear.cpp
@@ -501,7 +501,7 @@ void testHybrd1()
 /*      unless high solutions are required, */
 /*      this is the recommended setting. */
 
-  info = ei_hybrd1<myfunctor,VectorXd>(x, fvec, ei_sqrt(machine_epsilon<double>()));
+  info = ei_hybrd1<myfunctor,double>(x, fvec);
 
   // check return value
   VERIFY( 1 == info);
@@ -510,7 +510,7 @@ void testHybrd1()
   VERIFY_IS_APPROX(fvec.norm(), 1.192636e-08);
 
   // check x
-  VectorXd x_ref;
+  VectorXd x_ref(n);
   x_ref << -0.5706545, -0.6816283, -0.7017325, -0.7042129, -0.701369, -0.6918656, -0.665792, -0.5960342, -0.4164121;
   VERIFY_IS_APPROX(x, x_ref);
 }