diff --git a/Cantera/src/thermo/MetalPhase.h b/Cantera/src/thermo/MetalPhase.h
index a7bd456ec..1b90cbade 100644
--- a/Cantera/src/thermo/MetalPhase.h
+++ b/Cantera/src/thermo/MetalPhase.h
@@ -74,6 +74,16 @@ namespace Cantera {
             for (n = 0; n < nsp; n++) mu[n] = 0.0;
         }
 
+        virtual void getEnthalpy_RT(doublereal* hrt) const {
+            int n, nsp = nSpecies();
+            for (n = 0; n < nsp; n++) hrt[n] = 0.0;
+        }
+
+        virtual void getEntropy_R(doublereal* sr) const {
+            int n, nsp = nSpecies();
+            for (n = 0; n < nsp; n++) sr[n] = 0.0;
+        }
+
         virtual void getStandardChemPotentials(doublereal* mu0) const {
             int n, nsp = nSpecies();
             for (n = 0; n < nsp; n++) mu0[n] = 0.0;
diff --git a/Cantera/src/thermo/SurfPhase.h b/Cantera/src/thermo/SurfPhase.h
index 99b24dbac..55358f863 100644
--- a/Cantera/src/thermo/SurfPhase.h
+++ b/Cantera/src/thermo/SurfPhase.h
@@ -461,7 +461,7 @@ namespace Cantera {
      * @param hrt      Output vector of  nondimensional standard state enthalpies.
      *                 Length: m_kk.
      */
-    void getEnthalpy_RT(doublereal* hrt) const;
+    virtual void getEnthalpy_RT(doublereal* hrt) const;
 
     //! Get the array of nondimensional Entropy functions for the
     //! species standard states at the current <I>T</I> and <I>P</I> of the solution.
@@ -469,7 +469,7 @@ namespace Cantera {
      * @param sr   Output vector of  nondimensional standard state entropies.
      *             Length: m_kk.
      */
-    void getEntropy_R(doublereal* sr) const;
+    virtual void getEntropy_R(doublereal* sr) const;
 
     //! Get the nondimensional Heat Capacities at constant
     //! pressure for the species standard states