diff --git a/gtsam/discrete/discrete.i b/gtsam/discrete/discrete.i
index 55c8f9e22..d82ba9794 100644
--- a/gtsam/discrete/discrete.i
+++ b/gtsam/discrete/discrete.i
@@ -41,7 +41,7 @@ virtual class DiscreteFactor : gtsam::Factor {
              const gtsam::KeyFormatter& keyFormatter =
                  gtsam::DefaultKeyFormatter) const;
   bool equals(const gtsam::DiscreteFactor& other, double tol = 1e-9) const;
-  double operator()(const gtsam::DiscreteValues& values) const;
+  double operator()(const gtsam::Assignment<gtsam::Key>& values) const;
 };
 
 #include <gtsam/discrete/DecisionTreeFactor.h>
@@ -69,7 +69,7 @@ virtual class DecisionTreeFactor : gtsam::DiscreteFactor {
 
   size_t cardinality(gtsam::Key j) const;
   
-  double operator()(const gtsam::DiscreteValues& values) const;
+  double operator()(const gtsam::Assignment<gtsam::Key>& values) const;
   gtsam::DecisionTreeFactor operator*(const gtsam::DecisionTreeFactor& f) const;
   size_t cardinality(gtsam::Key j) const;
   gtsam::DecisionTreeFactor operator/(const gtsam::DecisionTreeFactor& f) const;
@@ -248,7 +248,6 @@ class DiscreteBayesTree {
   void saveGraph(string s,
                 const gtsam::KeyFormatter& keyFormatter =
                  gtsam::DefaultKeyFormatter) const;
-  double operator()(const gtsam::DiscreteValues& values) const;
 
   string markdown(const gtsam::KeyFormatter& keyFormatter =
                  gtsam::DefaultKeyFormatter) const;