diff --git a/gtsam/linear/NoiseModel.cpp b/gtsam/linear/NoiseModel.cpp
index a1f8c7570..5734c6c2e 100644
--- a/gtsam/linear/NoiseModel.cpp
+++ b/gtsam/linear/NoiseModel.cpp
@@ -490,6 +490,12 @@ void Base::reweight(Matrix &A1, Matrix &A2, Matrix &A3, Vector &error) const {
   }
 }
 
+void Null::print(const std::string &s) const
+{ cout << s << ": null ()" << endl; }
+
+Null::shared_ptr Null::Create()
+{ return shared_ptr(new Null()); }
+
 Fair::Fair(const double c, const ReweightScheme reweight)
   : Base(reweight), c_(c) {
   if ( c_ <= 0 ) {
diff --git a/gtsam/linear/NoiseModel.h b/gtsam/linear/NoiseModel.h
index f512035a1..14886d64d 100644
--- a/gtsam/linear/NoiseModel.h
+++ b/gtsam/linear/NoiseModel.h
@@ -514,7 +514,7 @@ namespace gtsam {
       ReweightScheme reweight_;
 
     public:
-		  Base():reweight_(Block) {}
+      Base(): reweight_(Block) {}
 		  Base(const ReweightScheme reweight):reweight_(reweight) {}
 		  virtual ~Base() {}
 		  virtual double weight(const double &error) const = 0;
@@ -526,6 +526,17 @@ namespace gtsam {
 		  void reweight(Matrix &A1, Matrix &A2, Matrix &A3, Vector &error) const;
 		};
 
+    class Null : public Base {
+    public:
+      typedef boost::shared_ptr<Null> shared_ptr;
+      Null(const ReweightScheme reweight = Block) : Base(reweight) {}
+      virtual ~Null() {}
+      virtual double weight(const double &error) const { return 1.0; }
+      virtual void print(const std::string &s) const ;
+      virtual bool equals(const Base& expected, const double tol=1e-8) const { return true; }
+      static shared_ptr Create() ;
+    };
+
 		class Fair : public Base {
 		public:
 		  typedef boost::shared_ptr<Fair> shared_ptr;