diff --git a/gtsam/linear/JacobianFactor.cpp b/gtsam/linear/JacobianFactor.cpp
index bb9d5afc0..a63bbf473 100644
--- a/gtsam/linear/JacobianFactor.cpp
+++ b/gtsam/linear/JacobianFactor.cpp
@@ -575,7 +575,7 @@ VectorValues JacobianFactor::gradientAtZero() const {
 
 /* ************************************************************************* */
 void JacobianFactor::gradientAtZero(double* d) const {
-  throw std::runtime_error("gradientAtZero not implemented for Jacobian factor");
+  //throw std::runtime_error("gradientAtZero not implemented for Jacobian factor");
 }
 
 /* ************************************************************************* */
diff --git a/gtsam_unstable/slam/ImplicitSchurFactor.h b/gtsam_unstable/slam/ImplicitSchurFactor.h
index 5c797fccd..c0f339b30 100644
--- a/gtsam_unstable/slam/ImplicitSchurFactor.h
+++ b/gtsam_unstable/slam/ImplicitSchurFactor.h
@@ -24,7 +24,6 @@ class ImplicitSchurFactor: public GaussianFactor {
 
 public:
   typedef ImplicitSchurFactor This; ///< Typedef to this class
-  typedef JacobianFactor Base; ///< Typedef to base class
   typedef boost::shared_ptr<This> shared_ptr; ///< shared_ptr to this class
 
 protected: