diff --git a/doc/sphinx/cxx-guide/demoequil.cpp b/doc/sphinx/cxx-guide/demoequil.cpp
index 4688c2959..f99707fc5 100644
--- a/doc/sphinx/cxx-guide/demoequil.cpp
+++ b/doc/sphinx/cxx-guide/demoequil.cpp
@@ -4,7 +4,7 @@ using namespace Cantera;
 
 void equil_demo()
 {
-    ThermoPhase* gas = newPhase("h2o2.cti","ohmech");
+    std::auto_ptr<ThermoPhase> gas(newPhase("h2o2.cti","ohmech"));
     gas->setState_TPX(1500.0, 2.0*OneAtm, "O2:1.0, H2:3.0, AR:1.0");
     gas->equilibrate("TP");
     std::cout << gas->report() << std::endl;
@@ -19,4 +19,3 @@ int main()
         std::cout << err.what() << std::endl;
     }
 }
-