diff --git a/gtsam/discrete/discrete.i b/gtsam/discrete/discrete.i
index d483782f3..91176601c 100644
--- a/gtsam/discrete/discrete.i
+++ b/gtsam/discrete/discrete.i
@@ -369,7 +369,7 @@ class DiscreteFactorGraph {
   void print(string s = "") const;
   bool equals(const gtsam::DiscreteFactorGraph& fg, double tol = 1e-9) const;
 
-  gtsam::DecisionTreeFactor product() const;
+  gtsam::DiscreteFactor* product() const;
   double operator()(const gtsam::DiscreteValues& values) const;
   gtsam::DiscreteValues optimize() const;