diff --git a/gtsam/discrete/tests/testDiscreteFactorGraph.cpp b/gtsam/discrete/tests/testDiscreteFactorGraph.cpp
index 0fbf44097..7a0e1eaf7 100644
--- a/gtsam/discrete/tests/testDiscreteFactorGraph.cpp
+++ b/gtsam/discrete/tests/testDiscreteFactorGraph.cpp
@@ -19,6 +19,7 @@
 #include <gtsam/discrete/DiscreteFactorGraph.h>
 #include <gtsam/discrete/DiscreteEliminationTree.h>
 #include <gtsam/discrete/DiscreteBayesTree.h>
+#include <gtsam/inference/BayesNet-inst.h>
 
 #include <CppUnitLite/TestHarness.h>