diff --git a/include/cantera/thermo/MixtureFugacityTP.h b/include/cantera/thermo/MixtureFugacityTP.h
index 20e12f5e5..99db095cb 100644
--- a/include/cantera/thermo/MixtureFugacityTP.h
+++ b/include/cantera/thermo/MixtureFugacityTP.h
@@ -338,7 +338,6 @@ public:
 
     virtual void getEnthalpy_RT_ref(doublereal* hrt) const;
     virtual void getGibbs_RT_ref(doublereal* grt) const;
-    virtual void modifyOneHf298SS(const size_t k, const doublereal Hf298New);
 
 protected:
     //! Returns the vector of nondimensional Gibbs free energies of the
diff --git a/include/cantera/thermo/VPStandardStateTP.h b/include/cantera/thermo/VPStandardStateTP.h
index 34b3b448a..0ca82b1f9 100644
--- a/include/cantera/thermo/VPStandardStateTP.h
+++ b/include/cantera/thermo/VPStandardStateTP.h
@@ -228,7 +228,6 @@ public:
     //@{
 
     virtual void getEnthalpy_RT_ref(doublereal* hrt) const;
-    virtual void modifyOneHf298SS(const size_t k, const doublereal Hf298New);
     virtual void getGibbs_RT_ref(doublereal* grt) const;
 
 protected:
diff --git a/src/thermo/MixtureFugacityTP.cpp b/src/thermo/MixtureFugacityTP.cpp
index 8ea24f615..dd377897e 100644
--- a/src/thermo/MixtureFugacityTP.cpp
+++ b/src/thermo/MixtureFugacityTP.cpp
@@ -111,12 +111,6 @@ void MixtureFugacityTP::getEnthalpy_RT(doublereal* hrt) const
     getEnthalpy_RT_ref(hrt);
 }
 
-void MixtureFugacityTP::modifyOneHf298SS(const size_t k, const doublereal Hf298New)
-{
-    m_spthermo->modifyOneHf298(k, Hf298New);
-    invalidateCache();
-}
-
 void MixtureFugacityTP::getEntropy_R(doublereal* sr) const
 {
     _updateReferenceStateThermo();
diff --git a/src/thermo/VPStandardStateTP.cpp b/src/thermo/VPStandardStateTP.cpp
index c9ce80647..2ebc436b9 100644
--- a/src/thermo/VPStandardStateTP.cpp
+++ b/src/thermo/VPStandardStateTP.cpp
@@ -129,12 +129,6 @@ void VPStandardStateTP::getEnthalpy_RT(doublereal* hrt) const
     m_VPSS_ptr->getEnthalpy_RT(hrt);
 }
 
-void VPStandardStateTP::modifyOneHf298SS(const size_t k, const doublereal Hf298New)
-{
-    m_spthermo->modifyOneHf298(k, Hf298New);
-    invalidateCache();
-}
-
 void VPStandardStateTP::getEntropy_R(doublereal* srt) const
 {
     updateStandardStateThermo();