diff --git a/include/cantera/thermo/MixedSolventElectrolyte.h b/include/cantera/thermo/MixedSolventElectrolyte.h
index 689b19a239..3c046da651 100644
--- a/include/cantera/thermo/MixedSolventElectrolyte.h
+++ b/include/cantera/thermo/MixedSolventElectrolyte.h
@@ -214,6 +214,7 @@ namespace Cantera
  * \f$k^{-1} \f$ has units of s-1.
  *
  *  @ingroup thermoprops
+ *  @deprecated To be removed after Cantera 2.4.
  */
 class MixedSolventElectrolyte : public MolarityIonicVPSSTP
 {
diff --git a/src/thermo/MixedSolventElectrolyte.cpp b/src/thermo/MixedSolventElectrolyte.cpp
index 609f771fad..e6c34783f7 100644
--- a/src/thermo/MixedSolventElectrolyte.cpp
+++ b/src/thermo/MixedSolventElectrolyte.cpp
@@ -20,6 +20,8 @@ MixedSolventElectrolyte::MixedSolventElectrolyte() :
     formMargules_(0),
     formTempModel_(0)
 {
+    warn_deprecated("class MixedSolventElectrolyte",
+                    "To be removed after Cantera 2.4");
 }
 
 MixedSolventElectrolyte::MixedSolventElectrolyte(const std::string& inputFile,
@@ -28,6 +30,8 @@ MixedSolventElectrolyte::MixedSolventElectrolyte(const std::string& inputFile,
     formMargules_(0),
     formTempModel_(0)
 {
+    warn_deprecated("class MixedSolventElectrolyte",
+                    "To be removed after Cantera 2.4");
     initThermoFile(inputFile, id_);
 }
 
@@ -37,6 +41,8 @@ MixedSolventElectrolyte::MixedSolventElectrolyte(XML_Node& phaseRoot,
     formMargules_(0),
     formTempModel_(0)
 {
+    warn_deprecated("class MixedSolventElectrolyte",
+                    "To be removed after Cantera 2.4");
     importPhase(phaseRoot, this);
 }
 
diff --git a/src/thermo/ThermoFactory.cpp b/src/thermo/ThermoFactory.cpp
index 155fcb3359..316687753f 100644
--- a/src/thermo/ThermoFactory.cpp
+++ b/src/thermo/ThermoFactory.cpp
@@ -38,7 +38,6 @@
 #include "cantera/thermo/DebyeHuckel.h"
 #include "cantera/thermo/IdealMolalSoln.h"
 #include "cantera/thermo/MolarityIonicVPSSTP.h"
-#include "cantera/thermo/MixedSolventElectrolyte.h"
 #include "cantera/thermo/IdealSolnGasVPSS.h"
 #include "cantera/base/stringUtils.h"