diff --git a/gtsam_unstable/nonlinear/Expression-inl.h b/gtsam_unstable/nonlinear/Expression-inl.h
index 2dcf5b43f..c2f51ea96 100644
--- a/gtsam_unstable/nonlinear/Expression-inl.h
+++ b/gtsam_unstable/nonlinear/Expression-inl.h
@@ -136,13 +136,15 @@ public:
 
 //-----------------------------------------------------------------------------
 struct JacobianTrace {
+  virtual ~JacobianTrace() {
+  }
   virtual void reverseAD(JacobianMap& jacobians) const = 0;
   virtual void reverseAD(const Matrix& dFdT, JacobianMap& jacobians) const = 0;
 //  template<class JacobianFT>
 //  void reverseAD(const JacobianFT& dFdT, JacobianMap& jacobians) const {
 };
 
-typedef boost::shared_ptr<JacobianTrace> TracePtr;
+typedef JacobianTrace* TracePtr;
 
 //template <class Derived>
 //struct TypedTrace {
@@ -235,7 +237,7 @@ public:
 
   /// Construct an execution trace for reverse AD
   virtual std::pair<T, TracePtr> traceExecution(const Values& values) const {
-    boost::shared_ptr<Trace> trace = boost::make_shared<Trace>();
+    Trace* trace = new Trace();
     return std::make_pair(constant_, trace);
   }
 };
@@ -298,7 +300,7 @@ public:
 
   /// Construct an execution trace for reverse AD
   virtual std::pair<T, TracePtr> traceExecution(const Values& values) const {
-    boost::shared_ptr<Trace> trace = boost::make_shared<Trace>();
+    Trace* trace = new Trace();
     trace->key = key_;
     return std::make_pair(values.at<T>(key_), trace);
   }
@@ -357,6 +359,9 @@ public:
   struct Trace: public JacobianTrace {
     TracePtr trace;
     JacobianTA dTdA;
+    virtual ~Trace() {
+      delete trace;
+    }
     /// Start the reverse AD process
     virtual void reverseAD(JacobianMap& jacobians) const {
       trace->reverseAD(dTdA, jacobians);
@@ -370,9 +375,9 @@ public:
   /// Construct an execution trace for reverse AD
   virtual std::pair<T, TracePtr> traceExecution(const Values& values) const {
     A a;
-    boost::shared_ptr<Trace> trace = boost::make_shared<Trace>();
+    Trace* trace = new Trace();
     boost::tie(a, trace->trace) = this->expressionA_->traceExecution(values);
-    return std::make_pair(function_(a, trace->dTdA),trace);
+    return std::make_pair(function_(a, trace->dTdA), trace);
   }
 };
 
@@ -443,6 +448,10 @@ public:
     TracePtr trace1, trace2;
     JacobianTA1 dTdA1;
     JacobianTA2 dTdA2;
+    virtual ~Trace() {
+      delete trace1;
+      delete trace2;
+    }
     /// Start the reverse AD process
     virtual void reverseAD(JacobianMap& jacobians) const {
       trace1->reverseAD(dTdA1, jacobians);
@@ -459,7 +468,7 @@ public:
   virtual std::pair<T, TracePtr> traceExecution(const Values& values) const {
     A1 a1;
     A2 a2;
-    boost::shared_ptr<Trace> trace = boost::make_shared<Trace>();
+    Trace* trace = new Trace();
     boost::tie(a1, trace->trace1) = this->expressionA1_->traceExecution(values);
     boost::tie(a2, trace->trace2) = this->expressionA2_->traceExecution(values);
     return std::make_pair(function_(a1, a2, trace->dTdA1, trace->dTdA2), trace);
@@ -543,12 +552,15 @@ public:
 
   /// Trace structure for reverse AD
   struct Trace: public JacobianTrace {
-    TracePtr trace1;
-    TracePtr trace2;
-    TracePtr trace3;
+    TracePtr trace1, trace2, trace3;
     JacobianTA1 dTdA1;
     JacobianTA2 dTdA2;
     JacobianTA3 dTdA3;
+    virtual ~Trace() {
+      delete trace1;
+      delete trace2;
+      delete trace3;
+    }
     /// Start the reverse AD process
     virtual void reverseAD(JacobianMap& jacobians) const {
       trace1->reverseAD(dTdA1, jacobians);
@@ -568,7 +580,7 @@ public:
     A1 a1;
     A2 a2;
     A3 a3;
-    boost::shared_ptr<Trace> trace = boost::make_shared<Trace>();
+    Trace* trace = new Trace();
     boost::tie(a1, trace->trace1) = this->expressionA1_->traceExecution(values);
     boost::tie(a2, trace->trace2) = this->expressionA2_->traceExecution(values);
     boost::tie(a3, trace->trace3) = this->expressionA3_->traceExecution(values);
diff --git a/gtsam_unstable/nonlinear/Expression.h b/gtsam_unstable/nonlinear/Expression.h
index 968a0f814..cc7977a23 100644
--- a/gtsam_unstable/nonlinear/Expression.h
+++ b/gtsam_unstable/nonlinear/Expression.h
@@ -122,6 +122,7 @@ public:
     boost::tie(value,trace) = root_->traceExecution(values);
     Augmented<T> augmented(value);
     trace->reverseAD(augmented.jacobians());
+    delete trace;
     return augmented;
 #else
     return root_->forward(values);