diff --git a/gtsam/linear/PCGSolver.cpp b/gtsam/linear/PCGSolver.cpp
index 5ec6fa67b..320c3e535 100644
--- a/gtsam/linear/PCGSolver.cpp
+++ b/gtsam/linear/PCGSolver.cpp
@@ -40,7 +40,7 @@ void PCGSolverParameters::print(ostream &os) const {
 /*****************************************************************************/
 PCGSolver::PCGSolver(const PCGSolverParameters &p) {
   parameters_ = p;
-  preconditioner_ = createPreconditioner(p.preconditioner_);
+  preconditioner_ = createPreconditioner(p.preconditioner());
 }
 
 void PCGSolverParameters::setPreconditionerParams(const std::shared_ptr<PreconditionerParameters> preconditioner) {
diff --git a/gtsam/linear/PCGSolver.h b/gtsam/linear/PCGSolver.h
index 5ed2c7c6d..35f6bdacb 100644
--- a/gtsam/linear/PCGSolver.h
+++ b/gtsam/linear/PCGSolver.h
@@ -34,26 +34,30 @@ struct PreconditionerParameters;
  * Parameters for PCG
  */
 struct GTSAM_EXPORT PCGSolverParameters: public ConjugateGradientParameters {
-public:
+ public:
   typedef ConjugateGradientParameters Base;
   typedef std::shared_ptr<PCGSolverParameters> shared_ptr;
 
-  PCGSolverParameters() {
-  }
+protected:
+  std::shared_ptr<PreconditionerParameters> preconditioner_;
+
+public:
+  PCGSolverParameters() {}
+
+  PCGSolverParameters(
+      const std::shared_ptr<PreconditionerParameters> &preconditioner)
+      : preconditioner_(preconditioner) {}
 
   void print(std::ostream &os) const override;
 
-  /* interface to preconditioner parameters */
-  inline const PreconditionerParameters& preconditioner() const {
-    return *preconditioner_;
+  const std::shared_ptr<PreconditionerParameters> preconditioner() const {
+    return preconditioner_;
   }
 
-  // needed for python wrapper
+  void setPreconditionerParams(
+      const std::shared_ptr<PreconditionerParameters> preconditioner);
+
   void print(const std::string &s) const;
-
-  std::shared_ptr<PreconditionerParameters> preconditioner_;
-
-  void setPreconditionerParams(const std::shared_ptr<PreconditionerParameters> preconditioner);
 };
 
 /**
diff --git a/gtsam/sfm/ShonanAveraging.cpp b/gtsam/sfm/ShonanAveraging.cpp
index 7c8b07f37..830f1c719 100644
--- a/gtsam/sfm/ShonanAveraging.cpp
+++ b/gtsam/sfm/ShonanAveraging.cpp
@@ -67,20 +67,15 @@ ShonanAveragingParameters<d>::ShonanAveragingParameters(
   builderParameters.augmentationWeight = SubgraphBuilderParameters::SKELETON;
   builderParameters.augmentationFactor = 0.0;
 
-  auto pcg = std::make_shared<PCGSolverParameters>();
-
   // Choose optimization method
   if (method == "SUBGRAPH") {
     lm.iterativeParams =
         std::make_shared<SubgraphSolverParameters>(builderParameters);
   } else if (method == "SGPC") {
-    pcg->preconditioner_ =
-        std::make_shared<SubgraphPreconditionerParameters>(builderParameters);
-    lm.iterativeParams = pcg;
+    lm.iterativeParams = std::make_shared<PCGSolverParameters>(
+        std::make_shared<SubgraphPreconditionerParameters>(builderParameters));
   } else if (method == "JACOBI") {
-    pcg->preconditioner_ =
-        std::make_shared<BlockJacobiPreconditionerParameters>();
-    lm.iterativeParams = pcg;
+    lm.iterativeParams = std::make_shared<PCGSolverParameters>(std::make_shared<BlockJacobiPreconditionerParameters>());
   } else if (method == "QR") {
     lm.setLinearSolverType("MULTIFRONTAL_QR");
   } else if (method == "CHOLESKY") {