diff --git a/gtsam/base/Manifold.h b/gtsam/base/Manifold.h
index d7ea9ea4c..6746236be 100644
--- a/gtsam/base/Manifold.h
+++ b/gtsam/base/Manifold.h
@@ -187,8 +187,8 @@ public:
   typedef Eigen::Matrix<double, dimension, 1> TangentVector;
   typedef OptionalJacobian<dimension, dimension> ChartJacobian;
 
-  /// Default constructor yields identity
-  ProductManifold():std::pair<M1,M2>(traits<M1>::Identity(),traits<M2>::Identity()) {}
+  /// Default constructor needs default constructors to be defined
+  ProductManifold():std::pair<M1,M2>(M1(),M2()) {}
 
   // Construct from two original manifold values
   ProductManifold(const M1& m1, const M2& m2):std::pair<M1,M2>(m1,m2) {}