diff --git a/unsupported/Eigen/src/AutoDiff/AutoDiffScalar.h b/unsupported/Eigen/src/AutoDiff/AutoDiffScalar.h
index 8d42e69b9..fde3ff61a 100644
--- a/unsupported/Eigen/src/AutoDiff/AutoDiffScalar.h
+++ b/unsupported/Eigen/src/AutoDiff/AutoDiffScalar.h
@@ -631,7 +631,7 @@ template<typename DerType> struct NumTraits<AutoDiffScalar<DerType> >
 {
   typedef AutoDiffScalar<Matrix<typename NumTraits<typename DerType::Scalar>::Real,DerType::RowsAtCompileTime,DerType::ColsAtCompileTime> > Real;
   typedef AutoDiffScalar<DerType> NonInteger;
-  typedef AutoDiffScalar<DerType>& Nested;
+  typedef AutoDiffScalar<DerType> Nested;
   enum{
     RequireInitialization = 1
   };