diff --git a/gtsam/hybrid/HybridFactorGraph.cpp b/gtsam/hybrid/HybridFactorGraph.cpp
index b72f50e8d..cb961b807 100644
--- a/gtsam/hybrid/HybridFactorGraph.cpp
+++ b/gtsam/hybrid/HybridFactorGraph.cpp
@@ -37,6 +37,7 @@
 #include <gtsam/linear/GaussianConditional.h>
 #include <gtsam/linear/GaussianEliminationTree.h>
 #include <gtsam/linear/GaussianFactorGraph.h>
+#include <gtsam/linear/GaussianJunctionTree.h>
 #include <gtsam/linear/HessianFactor.h>
 #include <gtsam/linear/JacobianFactor.h>