diff --git a/gtsam/linear/HessianFactor.cpp b/gtsam/linear/HessianFactor.cpp
index c93035d42..a56e02461 100644
--- a/gtsam/linear/HessianFactor.cpp
+++ b/gtsam/linear/HessianFactor.cpp
@@ -363,6 +363,12 @@ VectorValues HessianFactor::hessianDiagonal() const {
   return d;
 }
 
+/* ************************************************************************* */
+map<Key,Matrix> HessianFactor::hessianBlockDiagonal() const {
+  map<Key,Matrix> blocks;
+  return blocks;
+}
+
 /* ************************************************************************* */
 Matrix HessianFactor::augmentedJacobian() const
 {
diff --git a/gtsam/linear/JacobianFactor.cpp b/gtsam/linear/JacobianFactor.cpp
index f7d550390..66f7a5f05 100644
--- a/gtsam/linear/JacobianFactor.cpp
+++ b/gtsam/linear/JacobianFactor.cpp
@@ -455,6 +455,12 @@ namespace gtsam {
     return d;
   }
 
+  /* ************************************************************************* */
+  map<Key,Matrix> JacobianFactor::hessianBlockDiagonal() const {
+    map<Key,Matrix> blocks;
+    return blocks;
+  }
+
   /* ************************************************************************* */
   Vector JacobianFactor::operator*(const VectorValues& x) const {
     Vector Ax = zero(Ab_.rows());