diff --git a/gtsam/hybrid/HybridBayesNet.h b/gtsam/hybrid/HybridBayesNet.h
index 86fc9527a..fb05e2407 100644
--- a/gtsam/hybrid/HybridBayesNet.h
+++ b/gtsam/hybrid/HybridBayesNet.h
@@ -224,8 +224,9 @@ class GTSAM_EXPORT HybridBayesNet : public BayesNet<HybridConditional> {
    * assignment.
    * @return A pruned HybridBayesNet
    */
-  HybridBayesNet prune(size_t maxNrLeaves,
-                       const std::optional<double> &deadModeThreshold) const;
+  HybridBayesNet prune(
+      size_t maxNrLeaves,
+      const std::optional<double> &deadModeThreshold = {}) const;
 
   /**
    * @brief Error method using HybridValues which returns specific error for
diff --git a/gtsam/hybrid/tests/testHybridBayesNet.cpp b/gtsam/hybrid/tests/testHybridBayesNet.cpp
index 56e93499b..86dcd48e4 100644
--- a/gtsam/hybrid/tests/testHybridBayesNet.cpp
+++ b/gtsam/hybrid/tests/testHybridBayesNet.cpp
@@ -434,7 +434,7 @@ TEST(HybridBayesNet, RemoveDeadNodes) {
   HybridValues delta = posterior->optimize();
 
   // Prune the Bayes net
-  const bool pruneDeadVariables = true;
+  const double pruneDeadVariables = 0.99;
   auto prunedBayesNet = posterior->prune(2, pruneDeadVariables);
 
   // Check that discrete joint only has M0 and not (M0, M1)
@@ -445,11 +445,12 @@ TEST(HybridBayesNet, RemoveDeadNodes) {
   // Check that hybrid conditionals that only depend on M1
   // are now Gaussian and not Hybrid
   EXPECT(prunedBayesNet.at(0)->isDiscrete());
-  EXPECT(prunedBayesNet.at(1)->isHybrid());
+  EXPECT(prunedBayesNet.at(1)->isDiscrete());
+  EXPECT(prunedBayesNet.at(2)->isHybrid());
   // Only P(X2 | X1, M1) depends on M1,
   // so it gets convert to a Gaussian P(X2 | X1)
-  EXPECT(prunedBayesNet.at(2)->isContinuous());
-  EXPECT(prunedBayesNet.at(3)->isHybrid());
+  EXPECT(prunedBayesNet.at(3)->isContinuous());
+  EXPECT(prunedBayesNet.at(4)->isHybrid());
 }
 
 /* ****************************************************************************/