diff --git a/gtsam/hybrid/tests/testHybridNonlinearISAM.cpp b/gtsam/hybrid/tests/testHybridNonlinearISAM.cpp
index db0dc73c3..8b5bb41ac 100644
--- a/gtsam/hybrid/tests/testHybridNonlinearISAM.cpp
+++ b/gtsam/hybrid/tests/testHybridNonlinearISAM.cpp
@@ -357,10 +357,9 @@ TEST(HybridNonlinearISAM, Incremental_approximate) {
   // Run update with pruning
   size_t maxComponents = 5;
   incrementalHybrid.update(graph1, initial);
+  incrementalHybrid.prune(maxComponents);
   HybridGaussianISAM bayesTree = incrementalHybrid.bayesTree();
 
-  bayesTree.prune(maxComponents);
-
   // Check if we have a bayes tree with 4 hybrid nodes,
   // each with 2, 4, 8, and 5 (pruned) leaves respetively.
   EXPECT_LONGS_EQUAL(4, bayesTree.size());
@@ -382,10 +381,9 @@ TEST(HybridNonlinearISAM, Incremental_approximate) {
 
   // Run update with pruning a second time.
   incrementalHybrid.update(graph2, initial);
+  incrementalHybrid.prune(maxComponents);
   bayesTree = incrementalHybrid.bayesTree();
 
-  bayesTree.prune(maxComponents);
-
   // Check if we have a bayes tree with pruned hybrid nodes,
   // with 5 (pruned) leaves.
   CHECK_EQUAL(5, bayesTree.size());