diff --git a/gtsam/discrete/AlgebraicDecisionTree.h b/gtsam/discrete/AlgebraicDecisionTree.h
index 9769715a1..2c749a471 100644
--- a/gtsam/discrete/AlgebraicDecisionTree.h
+++ b/gtsam/discrete/AlgebraicDecisionTree.h
@@ -156,9 +156,9 @@ namespace gtsam {
     }
 
     /// print method customized to value type `double`.
-    void print(const std::string& s,
-              const typename Base::LabelFormatter& labelFormatter =
-                  &DefaultFormatter) const {
+    void print(const std::string& s = "",
+               const typename Base::LabelFormatter& labelFormatter =
+                   &DefaultFormatter) const {
       auto valueFormatter = [](const double& v) {
         return (boost::format("%4.8g") % v).str();
       };