diff --git a/src/thermo/ThermoFactory.cpp b/src/thermo/ThermoFactory.cpp
index e55738634..8bfc2c527 100644
--- a/src/thermo/ThermoFactory.cpp
+++ b/src/thermo/ThermoFactory.cpp
@@ -168,19 +168,19 @@ std::string eosTypeString(int ieos, int length)
 ThermoPhase* newPhase(XML_Node& xmlphase)
 {
     string model = xmlphase.child("thermo")["model"];
-    ThermoPhase* t = newThermoPhase(model);
+    unique_ptr<ThermoPhase> t(newThermoPhase(model));
     if (model == "singing cows") {
         throw CanteraError("ThermoPhase::newPhase", "Cows don't sing");
     } else if (model == "HMW") {
-        HMWSoln* p = dynamic_cast<HMWSoln*>(t);
+        HMWSoln* p = dynamic_cast<HMWSoln*>(t.get());
         p->constructPhaseXML(xmlphase,"");
     } else if (model == "IonsFromNeutralMolecule") {
-        IonsFromNeutralVPSSTP* p = dynamic_cast<IonsFromNeutralVPSSTP*>(t);
+        IonsFromNeutralVPSSTP* p = dynamic_cast<IonsFromNeutralVPSSTP*>(t.get());
         p->constructPhaseXML(xmlphase,"");
     } else {
-        importPhase(xmlphase, t);
+        importPhase(xmlphase, t.get());
     }
-    return t;
+    return t.release();
 }
 
 ThermoPhase* newPhase(const std::string& infile, std::string id)