diff --git a/gtsam/hybrid/HybridGaussianConditional.cpp b/gtsam/hybrid/HybridGaussianConditional.cpp
index 2a0b5a875b..58724163ec 100644
--- a/gtsam/hybrid/HybridGaussianConditional.cpp
+++ b/gtsam/hybrid/HybridGaussianConditional.cpp
@@ -22,7 +22,6 @@
 #include <gtsam/discrete/DiscreteValues.h>
 #include <gtsam/hybrid/HybridGaussianConditional.h>
 #include <gtsam/hybrid/HybridGaussianFactor.h>
-#include <gtsam/hybrid/HybridGaussianProductFactor.h>
 #include <gtsam/hybrid/HybridValues.h>
 #include <gtsam/inference/Conditional-inst.h>
 #include <gtsam/linear/GaussianBayesNet.h>
diff --git a/gtsam/hybrid/HybridGaussianConditional.h b/gtsam/hybrid/HybridGaussianConditional.h
index 75138b0dc2..4cc3d31960 100644
--- a/gtsam/hybrid/HybridGaussianConditional.h
+++ b/gtsam/hybrid/HybridGaussianConditional.h
@@ -26,7 +26,6 @@
 #include <gtsam/discrete/DiscreteKey.h>
 #include <gtsam/hybrid/HybridFactor.h>
 #include <gtsam/hybrid/HybridGaussianFactor.h>
-#include <gtsam/hybrid/HybridGaussianProductFactor.h>
 #include <gtsam/inference/Conditional.h>
 #include <gtsam/linear/GaussianConditional.h>
 
diff --git a/gtsam/hybrid/HybridGaussianProductFactor.cpp b/gtsam/hybrid/HybridGaussianProductFactor.cpp
index f7b5994f0f..280059f542 100644
--- a/gtsam/hybrid/HybridGaussianProductFactor.cpp
+++ b/gtsam/hybrid/HybridGaussianProductFactor.cpp
@@ -103,4 +103,10 @@ HybridGaussianProductFactor HybridGaussianProductFactor::removeEmpty() const {
   return {Base(*this, emptyGaussian)};
 }
 
+/* *******************************************************************************/
+std::istream& operator>>(std::istream& is, GaussianFactorGraphValuePair& pair) {
+  // Dummy, don't do anything
+  return is;
+}
+
 }  // namespace gtsam
diff --git a/gtsam/hybrid/HybridGaussianProductFactor.h b/gtsam/hybrid/HybridGaussianProductFactor.h
index 508113e874..60a58a3a51 100644
--- a/gtsam/hybrid/HybridGaussianProductFactor.h
+++ b/gtsam/hybrid/HybridGaussianProductFactor.h
@@ -22,6 +22,8 @@
 #include <gtsam/inference/Key.h>
 #include <gtsam/linear/GaussianFactorGraph.h>
 
+#include <iostream>
+
 namespace gtsam {
 
 class HybridGaussianFactor;
@@ -115,6 +117,16 @@ class GTSAM_EXPORT HybridGaussianProductFactor
   HybridGaussianProductFactor removeEmpty() const;
 
   ///@}
+
+ private:
+#ifdef GTSAM_ENABLE_BOOST_SERIALIZATION
+  /** Serialization function */
+  friend class boost::serialization::access;
+  template <class Archive>
+  void serialize(Archive& ar, const unsigned int /*version*/) {
+    ar& BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
+  }
+#endif
 };
 
 // Testable traits
@@ -122,4 +134,14 @@ template <>
 struct traits<HybridGaussianProductFactor>
     : public Testable<HybridGaussianProductFactor> {};
 
+/**
+ * Create a dummy overload of >> for GaussianFactorGraphValuePair
+ * so that HybridGaussianProductFactor compiles
+ * with the constructor
+ * `DecisionTree(const std::vector<LabelC>& labelCs, const std::string& table)`.
+ *
+ * Needed to compile on Windows.
+ */
+std::istream& operator>>(std::istream& is, GaussianFactorGraphValuePair& pair);
+
 }  // namespace gtsam
diff --git a/gtsam/hybrid/tests/testHybridGaussianFactor.cpp b/gtsam/hybrid/tests/testHybridGaussianFactor.cpp
index 71aac8224b..05e05c79b7 100644
--- a/gtsam/hybrid/tests/testHybridGaussianFactor.cpp
+++ b/gtsam/hybrid/tests/testHybridGaussianFactor.cpp
@@ -104,13 +104,12 @@ TEST(HybridGaussianFactor, Keys) {
 }
 
 /* ************************************************************************* */
-TEST_DISABLED(HybridGaussianFactor, Printing) {
+TEST(HybridGaussianFactor, Printing) {
   using namespace test_constructor;
   HybridGaussianFactor hybridFactor(m1, {f10, f11});
 
   std::string expected =
-      R"(HybridGaussianFactor
-Hybrid [x1 x2; 1]{
+      R"(Hybrid [x1 x2; 1]{
  Choice(1) 
  0 Leaf :
   A[x1] = [
diff --git a/gtsam/hybrid/tests/testHybridNonlinearFactorGraph.cpp b/gtsam/hybrid/tests/testHybridNonlinearFactorGraph.cpp
index b5486c6cdb..bbf427ecb2 100644
--- a/gtsam/hybrid/tests/testHybridNonlinearFactorGraph.cpp
+++ b/gtsam/hybrid/tests/testHybridNonlinearFactorGraph.cpp
@@ -529,7 +529,7 @@ TEST(HybridNonlinearFactorGraph, Full_Elimination) {
 /****************************************************************************
  * Test printing
  */
-TEST_DISABLED(HybridNonlinearFactorGraph, Printing) {
+TEST(HybridNonlinearFactorGraph, Printing) {
   Switching self(3);
 
   auto linearizedFactorGraph = self.linearizedFactorGraph;
@@ -549,7 +549,7 @@ Factor 0
 GaussianFactor:
 
   A[x0] = [
-        10
+	10
 ]
   b = [ -10 ]
   No noise model
@@ -560,25 +560,25 @@ Hybrid [x0 x1; m0]{
  Choice(m0) 
  0 Leaf :
   A[x0] = [
-        -1
+	-1
 ]
   A[x1] = [
-        1
+	1
 ]
   b = [ -1 ]
   No noise model
-scalar: 0
+scalar: 0.918939
 
  1 Leaf :
   A[x0] = [
-        -1
+	-1
 ]
   A[x1] = [
-        1
+	1
 ]
   b = [ -0 ]
   No noise model
-scalar: 0
+scalar: 0.918939
 
 }
 
@@ -588,25 +588,25 @@ Hybrid [x1 x2; m1]{
  Choice(m1) 
  0 Leaf :
   A[x1] = [
-        -1
+	-1
 ]
   A[x2] = [
-        1
+	1
 ]
   b = [ -1 ]
   No noise model
-scalar: 0
+scalar: 0.918939
 
  1 Leaf :
   A[x1] = [
-        -1
+	-1
 ]
   A[x2] = [
-        1
+	1
 ]
   b = [ -0 ]
   No noise model
-scalar: 0
+scalar: 0.918939
 
 }
 
@@ -614,7 +614,7 @@ Factor 3
 GaussianFactor:
 
   A[x1] = [
-        10
+	10
 ]
   b = [ -10 ]
   No noise model
@@ -623,7 +623,7 @@ Factor 4
 GaussianFactor:
 
   A[x2] = [
-        10
+	10
 ]
   b = [ -10 ]
   No noise model
diff --git a/gtsam/hybrid/tests/testSerializationHybrid.cpp b/gtsam/hybrid/tests/testSerializationHybrid.cpp
index 8258d8615e..5b06312ba4 100644
--- a/gtsam/hybrid/tests/testSerializationHybrid.cpp
+++ b/gtsam/hybrid/tests/testSerializationHybrid.cpp
@@ -59,6 +59,11 @@ BOOST_CLASS_EXPORT_GUID(HybridGaussianFactor::FactorValuePairs::Leaf,
 BOOST_CLASS_EXPORT_GUID(HybridGaussianFactor::FactorValuePairs::Choice,
                         "gtsam_HybridGaussianFactor_Factors_Choice");
 
+BOOST_CLASS_EXPORT_GUID(GaussianFactorGraphValuePair,
+                        "gtsam_GaussianFactorGraphValuePair");
+BOOST_CLASS_EXPORT_GUID(HybridGaussianProductFactor,
+                        "gtsam_HybridGaussianProductFactor");
+
 BOOST_CLASS_EXPORT_GUID(HybridGaussianConditional,
                         "gtsam_HybridGaussianConditional");
 BOOST_CLASS_EXPORT_GUID(HybridGaussianConditional::Conditionals,