diff --git a/include/cantera/thermo/PDSS.h b/include/cantera/thermo/PDSS.h
index 6693bfd19..2eaeef3d4 100644
--- a/include/cantera/thermo/PDSS.h
+++ b/include/cantera/thermo/PDSS.h
@@ -213,6 +213,7 @@ public:
     //! Returns the type of the standard state parameterization
     /*!
      * @return The integer # of the parameterization
+     * @deprecated To be removed after Cantera 2.3.
      */
     PDSS_enumType reportPDSSType() const;
 
@@ -526,6 +527,7 @@ public:
 
 protected:
     //! Enumerated type describing the type of the PDSS object
+    //! @deprecated To be removed after Cantera 2.3.
     PDSS_enumType m_pdssType;
 
     //! Current temperature used by the PDSS object
diff --git a/include/cantera/thermo/VPSSMgr.h b/include/cantera/thermo/VPSSMgr.h
index 6c52c7f3b..11ac8fe14 100644
--- a/include/cantera/thermo/VPSSMgr.h
+++ b/include/cantera/thermo/VPSSMgr.h
@@ -564,6 +564,7 @@ public:
     //! species with index number index.
     /*!
      * @param index  Species index
+     * @deprecated To be removed after Cantera 2.3.
      */
     virtual PDSS_enumType reportPDSSType(int index = -1) const;
 
diff --git a/include/cantera/thermo/mix_defs.h b/include/cantera/thermo/mix_defs.h
index afeac7d94..d62224870 100644
--- a/include/cantera/thermo/mix_defs.h
+++ b/include/cantera/thermo/mix_defs.h
@@ -116,6 +116,7 @@ enum SSVolume_Model_enumType {
 };
 
 //! Types of PDSS's
+//! @deprecated Unused. To be removed after Cantera 2.3.
 enum PDSS_enumType {
     cPDSS_UNDEF = 100,
     cPDSS_IDEALGAS,
diff --git a/src/thermo/PDSS.cpp b/src/thermo/PDSS.cpp
index 3d5b7ea23..b05c38f66 100644
--- a/src/thermo/PDSS.cpp
+++ b/src/thermo/PDSS.cpp
@@ -155,6 +155,7 @@ PDSS* PDSS::duplMyselfAsPDSS() const
 
 PDSS_enumType PDSS::reportPDSSType() const
 {
+    warn_deprecated("PDSS::reportPDSSType", "To be removed after Cantera 2.3.");
     return m_pdssType;
 }
 
diff --git a/src/thermo/VPSSMgr_ConstVol.cpp b/src/thermo/VPSSMgr_ConstVol.cpp
index 24b8e186f..a6f00cbd1 100644
--- a/src/thermo/VPSSMgr_ConstVol.cpp
+++ b/src/thermo/VPSSMgr_ConstVol.cpp
@@ -141,6 +141,8 @@ PDSS* VPSSMgr_ConstVol::createInstallPDSS(size_t k, const XML_Node& speciesNode,
 
 PDSS_enumType VPSSMgr_ConstVol::reportPDSSType(int k) const
 {
+    warn_deprecated("VPSSMgr_ConstVol::reportPDSSType",
+        "To be removed after Cantera 2.3.");
     return cPDSS_CONSTVOL;
 }
 
diff --git a/src/thermo/VPSSMgr_General.cpp b/src/thermo/VPSSMgr_General.cpp
index 8e7185137..4837f075e 100644
--- a/src/thermo/VPSSMgr_General.cpp
+++ b/src/thermo/VPSSMgr_General.cpp
@@ -201,6 +201,8 @@ PDSS* VPSSMgr_General::createInstallPDSS(size_t k, const XML_Node& speciesNode,
 
 PDSS_enumType VPSSMgr_General::reportPDSSType(int k) const
 {
+    warn_deprecated("VPSSMgr_General::reportPDSSType",
+        "To be removed after Cantera 2.3.");
     return m_PDSS_ptrs[k]->reportPDSSType();
 }
 
diff --git a/src/thermo/VPSSMgr_IdealGas.cpp b/src/thermo/VPSSMgr_IdealGas.cpp
index 3dce262a9..8b4449c9b 100644
--- a/src/thermo/VPSSMgr_IdealGas.cpp
+++ b/src/thermo/VPSSMgr_IdealGas.cpp
@@ -106,6 +106,8 @@ PDSS* VPSSMgr_IdealGas::createInstallPDSS(size_t k, const XML_Node& speciesNode,
 
 PDSS_enumType VPSSMgr_IdealGas::reportPDSSType(int k) const
 {
+    warn_deprecated("VPSSMgr_IdealGas::reportPDSSType",
+        "To be removed after Cantera 2.3.");
     return cPDSS_IDEALGAS;
 }
 
diff --git a/src/thermo/VPSSMgr_Water_ConstVol.cpp b/src/thermo/VPSSMgr_Water_ConstVol.cpp
index 054de82c7..4fd5efef0 100644
--- a/src/thermo/VPSSMgr_Water_ConstVol.cpp
+++ b/src/thermo/VPSSMgr_Water_ConstVol.cpp
@@ -268,6 +268,8 @@ PDSS* VPSSMgr_Water_ConstVol::createInstallPDSS(size_t k,
 
 PDSS_enumType VPSSMgr_Water_ConstVol::reportPDSSType(int k) const
 {
+    warn_deprecated("VPSSMgr_Water_ConstVol::reportPDSSType",
+        "To be removed after Cantera 2.3.");
     return cPDSS_UNDEF;
 }
 
diff --git a/src/thermo/VPSSMgr_Water_HKFT.cpp b/src/thermo/VPSSMgr_Water_HKFT.cpp
index f74242ad9..1b51577de 100644
--- a/src/thermo/VPSSMgr_Water_HKFT.cpp
+++ b/src/thermo/VPSSMgr_Water_HKFT.cpp
@@ -269,6 +269,8 @@ void VPSSMgr_Water_HKFT::initAllPtrs(VPStandardStateTP* vp_ptr,
 
 PDSS_enumType VPSSMgr_Water_HKFT::reportPDSSType(int k) const
 {
+    warn_deprecated("VPSSMgr_Water_HKFT::reportPDSSType",
+        "To be removed after Cantera 2.3.");
     return cPDSS_UNDEF;
 }