diff --git a/gtsam/hybrid/HybridConditional.h b/gtsam/hybrid/HybridConditional.h
index da7c1421e..021ca1361 100644
--- a/gtsam/hybrid/HybridConditional.h
+++ b/gtsam/hybrid/HybridConditional.h
@@ -188,6 +188,19 @@ class GTSAM_EXPORT HybridConditional
     ar& BOOST_SERIALIZATION_BASE_OBJECT_NVP(BaseFactor);
     ar& BOOST_SERIALIZATION_BASE_OBJECT_NVP(BaseConditional);
     ar& BOOST_SERIALIZATION_NVP(inner_);
+
+    // register the various casts based on the type of inner_
+    // https://www.boost.org/doc/libs/1_80_0/libs/serialization/doc/serialization.html#runtimecasting
+    if (isDiscrete()) {
+      boost::serialization::void_cast_register<DiscreteConditional, Factor>(
+          static_cast<DiscreteConditional*>(NULL), static_cast<Factor*>(NULL));
+    } else if (isContinuous()) {
+      boost::serialization::void_cast_register<GaussianConditional, Factor>(
+          static_cast<GaussianConditional*>(NULL), static_cast<Factor*>(NULL));
+    } else {
+      boost::serialization::void_cast_register<GaussianMixture, Factor>(
+          static_cast<GaussianMixture*>(NULL), static_cast<Factor*>(NULL));
+    }
   }
 
 };  // HybridConditional
diff --git a/gtsam/hybrid/tests/testHybridBayesNet.cpp b/gtsam/hybrid/tests/testHybridBayesNet.cpp
index 43eebcf88..ef552bd92 100644
--- a/gtsam/hybrid/tests/testHybridBayesNet.cpp
+++ b/gtsam/hybrid/tests/testHybridBayesNet.cpp
@@ -18,7 +18,6 @@
  * @date    December 2021
  */
 
-#include <gtsam/base/serializationTestHelpers.h>
 #include <gtsam/hybrid/HybridBayesNet.h>
 #include <gtsam/hybrid/HybridBayesTree.h>
 #include <gtsam/nonlinear/NonlinearFactorGraph.h>
@@ -31,7 +30,6 @@
 
 using namespace std;
 using namespace gtsam;
-using namespace gtsam::serializationTestHelpers;
 
 using noiseModel::Isotropic;
 using symbol_shorthand::M;
@@ -330,20 +328,6 @@ TEST(HybridBayesNet, UpdateDiscreteConditionals) {
   discrete_conditional_tree->apply(checker);
 }
 
-/* ****************************************************************************/
-// Test HybridBayesNet serialization.
-TEST(HybridBayesNet, Serialization) {
-  Switching s(4);
-  Ordering ordering = s.linearizedFactorGraph.getHybridOrdering();
-  HybridBayesNet hbn = *(s.linearizedFactorGraph.eliminateSequential(ordering));
-
-  // TODO(Varun) Serialization of inner factor doesn't work. Requires
-  // serialization support for all hybrid factors.
-  //  EXPECT(equalsObj<HybridBayesNet>(hbn));
-  //  EXPECT(equalsXML<HybridBayesNet>(hbn));
-  //  EXPECT(equalsBinary<HybridBayesNet>(hbn));
-}
-
 /* ****************************************************************************/
 // Test HybridBayesNet sampling.
 TEST(HybridBayesNet, Sampling) {
diff --git a/gtsam/hybrid/tests/testHybridBayesTree.cpp b/gtsam/hybrid/tests/testHybridBayesTree.cpp
index 1e6510383..b957a67d0 100644
--- a/gtsam/hybrid/tests/testHybridBayesTree.cpp
+++ b/gtsam/hybrid/tests/testHybridBayesTree.cpp
@@ -220,22 +220,6 @@ TEST(HybridBayesTree, Choose) {
   EXPECT(assert_equal(expected_gbt, gbt));
 }
 
-/* ****************************************************************************/
-// Test HybridBayesTree serialization.
-TEST(HybridBayesTree, Serialization) {
-  Switching s(4);
-  Ordering ordering = s.linearizedFactorGraph.getHybridOrdering();
-  HybridBayesTree hbt =
-      *(s.linearizedFactorGraph.eliminateMultifrontal(ordering));
-
-  using namespace gtsam::serializationTestHelpers;
-  // TODO(Varun) Serialization of inner factor doesn't work. Requires
-  // serialization support for all hybrid factors.
-  // EXPECT(equalsObj<HybridBayesTree>(hbt));
-  // EXPECT(equalsXML<HybridBayesTree>(hbt));
-  // EXPECT(equalsBinary<HybridBayesTree>(hbt));
-}
-
 /* ************************************************************************* */
 int main() {
   TestResult tr;
diff --git a/gtsam/hybrid/tests/testSerializationHybrid.cpp b/gtsam/hybrid/tests/testSerializationHybrid.cpp
index 9597fe8f0..941a1cdb3 100644
--- a/gtsam/hybrid/tests/testSerializationHybrid.cpp
+++ b/gtsam/hybrid/tests/testSerializationHybrid.cpp
@@ -17,14 +17,19 @@
  */
 
 #include <gtsam/base/serializationTestHelpers.h>
+#include <gtsam/discrete/DiscreteConditional.h>
 #include <gtsam/hybrid/GaussianMixture.h>
 #include <gtsam/hybrid/GaussianMixtureFactor.h>
+#include <gtsam/hybrid/HybridBayesNet.h>
+#include <gtsam/hybrid/HybridBayesTree.h>
 #include <gtsam/hybrid/HybridConditional.h>
 #include <gtsam/hybrid/HybridDiscreteFactor.h>
 #include <gtsam/hybrid/HybridGaussianFactor.h>
 #include <gtsam/inference/Symbol.h>
 #include <gtsam/linear/GaussianConditional.h>
 
+#include "Switching.h"
+
 // Include for test suite
 #include <CppUnitLite/TestHarness.h>
 
@@ -36,15 +41,17 @@ using symbol_shorthand::Z;
 
 using namespace serializationTestHelpers;
 
+BOOST_CLASS_EXPORT_GUID(Factor, "gtsam_Factor");
 BOOST_CLASS_EXPORT_GUID(HybridFactor, "gtsam_HybridFactor");
 BOOST_CLASS_EXPORT_GUID(JacobianFactor, "gtsam_JacobianFactor");
 BOOST_CLASS_EXPORT_GUID(GaussianConditional, "gtsam_GaussianConditional");
+BOOST_CLASS_EXPORT_GUID(DiscreteConditional, "gtsam_DiscreteConditional");
 
 BOOST_CLASS_EXPORT_GUID(DecisionTreeFactor, "gtsam_DecisionTreeFactor");
 using ADT = AlgebraicDecisionTree<Key>;
 BOOST_CLASS_EXPORT_GUID(ADT, "gtsam_AlgebraicDecisionTree");
-BOOST_CLASS_EXPORT_GUID(ADT::Leaf, "gtsam_DecisionTree_Leaf");
-BOOST_CLASS_EXPORT_GUID(ADT::Choice, "gtsam_DecisionTree_Choice");
+BOOST_CLASS_EXPORT_GUID(ADT::Leaf, "gtsam_AlgebraicDecisionTree_Leaf");
+BOOST_CLASS_EXPORT_GUID(ADT::Choice, "gtsam_AlgebraicDecisionTree_Choice")
 
 BOOST_CLASS_EXPORT_GUID(GaussianMixtureFactor, "gtsam_GaussianMixtureFactor");
 BOOST_CLASS_EXPORT_GUID(GaussianMixtureFactor::Factors,
@@ -64,6 +71,8 @@ BOOST_CLASS_EXPORT_GUID(GaussianMixture::Conditionals::Choice,
 // Needed since GaussianConditional::FromMeanAndStddev uses it
 BOOST_CLASS_EXPORT_GUID(noiseModel::Isotropic, "gtsam_noiseModel_Isotropic");
 
+BOOST_CLASS_EXPORT_GUID(HybridBayesNet, "gtsam_HybridBayesNet");
+
 /* ****************************************************************************/
 // Test HybridGaussianFactor serialization.
 TEST(HybridSerialization, HybridGaussianFactor) {
@@ -137,6 +146,31 @@ TEST(HybridSerialization, GaussianMixture) {
   EXPECT(equalsBinary<GaussianMixture>(gm));
 }
 
+/* ****************************************************************************/
+// Test HybridBayesNet serialization.
+TEST(HybridSerialization, HybridBayesNet) {
+  Switching s(2);
+  Ordering ordering = s.linearizedFactorGraph.getHybridOrdering();
+  HybridBayesNet hbn = *(s.linearizedFactorGraph.eliminateSequential(ordering));
+
+  EXPECT(equalsObj<HybridBayesNet>(hbn));
+  EXPECT(equalsXML<HybridBayesNet>(hbn));
+  EXPECT(equalsBinary<HybridBayesNet>(hbn));
+}
+
+/* ****************************************************************************/
+// Test HybridBayesTree serialization.
+TEST(HybridSerialization, HybridBayesTree) {
+  Switching s(2);
+  Ordering ordering = s.linearizedFactorGraph.getHybridOrdering();
+  HybridBayesTree hbt =
+      *(s.linearizedFactorGraph.eliminateMultifrontal(ordering));
+
+  EXPECT(equalsObj<HybridBayesTree>(hbt));
+  EXPECT(equalsXML<HybridBayesTree>(hbt));
+  EXPECT(equalsBinary<HybridBayesTree>(hbt));
+}
+
 /* ************************************************************************* */
 int main() {
   TestResult tr;