diff --git a/doc/sphinx/cxx-guide/thermo.rst b/doc/sphinx/cxx-guide/thermo.rst
index 0813c89e4..eb5d39893 100644
--- a/doc/sphinx/cxx-guide/thermo.rst
+++ b/doc/sphinx/cxx-guide/thermo.rst
@@ -18,7 +18,8 @@ prints its temperature is shown below:
 
     int main(int argc, char** argv)
     {
-        Cantera::ThermoPhase* gas = Cantera::newPhase("h2o2.cti","ohmech");
+        std::unique_ptr<Cantera::ThermoPhase> gas(
+            Cantera::newPhase("h2o2.cti", "ohmech"));
         std::cout << gas->temperature() << std::endl;
         return 0;
     }
diff --git a/doc/sphinx/cxx-guide/thermodemo.cpp b/doc/sphinx/cxx-guide/thermodemo.cpp
index d92ec2a42..79d66fc7c 100644
--- a/doc/sphinx/cxx-guide/thermodemo.cpp
+++ b/doc/sphinx/cxx-guide/thermodemo.cpp
@@ -4,7 +4,7 @@ using namespace Cantera;
 
 void thermo_demo(const std::string& file, const std::string& phase)
 {
-    ThermoPhase* gas = newPhase(file, phase);
+    shared_ptr<ThermoPhase> gas(newPhase(file, phase));
     gas->setState_TPX(1500.0, 2.0*OneAtm, "O2:1.0, H2:3.0, AR:1.0");
 
     // temperature, pressure, and density