diff --git a/gtsam/discrete/TableFactor.cpp b/gtsam/discrete/TableFactor.cpp
index bf9662e34..67ba19d39 100644
--- a/gtsam/discrete/TableFactor.cpp
+++ b/gtsam/discrete/TableFactor.cpp
@@ -252,6 +252,11 @@ DecisionTreeFactor TableFactor::operator*(const DecisionTreeFactor& f) const {
 DecisionTreeFactor TableFactor::toDecisionTreeFactor() const {
   DiscreteKeys dkeys = discreteKeys();
 
+  // If no keys, then return empty DecisionTreeFactor
+  if (dkeys.size() == 0) {
+    return DecisionTreeFactor(dkeys, AlgebraicDecisionTree<Key>());
+  }
+
   std::vector<double> table;
   for (auto i = 0; i < sparse_table_.size(); i++) {
     table.push_back(sparse_table_.coeff(i));