diff --git a/MaterialLib/MPL/PropertyType.h b/MaterialLib/MPL/PropertyType.h
index 6fa0e4e2ce6138877653439380beeade7127357e..d577cd95b2f746d34df4e1b663217293853c0bd1 100644
--- a/MaterialLib/MPL/PropertyType.h
+++ b/MaterialLib/MPL/PropertyType.h
@@ -84,6 +84,7 @@ enum PropertyType : int
     /// capillary pressure saturation relationship for microstructure.
     saturation_micro,
     specific_heat_capacity,
+    specific_latent_heat,
     storage,
     swelling_stress_rate,
     thermal_conductivity,
@@ -281,6 +282,10 @@ inline PropertyType convertStringToProperty(std::string const& inString)
     {
         return PropertyType::specific_heat_capacity;
     }
+    if (boost::iequals(inString, "specific_latent_heat"))
+    {
+        return PropertyType::specific_latent_heat;
+    }
     if (boost::iequals(inString, "storage"))
     {
         return PropertyType::storage;
@@ -390,6 +395,7 @@ static const std::array<std::string, PropertyType::number_of_properties>
                              "saturation",
                              "saturation_micro",
                              "specific_heat_capacity",
+                             "specific_latent_heat",
                              "storage",
                              "swelling_stress_rate",
                              "thermal_conductivity",
diff --git a/MaterialLib/MPL/VariableType.cpp b/MaterialLib/MPL/VariableType.cpp
index ebf1195616cc090067b40091d689e1bf58da644e..eff244be6a8e0f3cf7d0325ac8c4bab613fb9529 100644
--- a/MaterialLib/MPL/VariableType.cpp
+++ b/MaterialLib/MPL/VariableType.cpp
@@ -62,6 +62,10 @@ Variable convertStringToVariable(std::string const& input)
     {
         return Variable::solid_grain_pressure;
     }
+    if (boost::iequals(input, "vapour_pressure"))
+    {
+        return Variable::vapour_pressure;
+    }
 
     OGS_FATAL(
         "The variable name '{:s}' does not correspond to any known variable",
diff --git a/MaterialLib/MPL/VariableType.h b/MaterialLib/MPL/VariableType.h
index 68ba0534d4c8cb42a22aa39294483a6953b4cadc..049e3e3f8cc6c6712fdfffc0e222a67e619802b9 100644
--- a/MaterialLib/MPL/VariableType.h
+++ b/MaterialLib/MPL/VariableType.h
@@ -51,9 +51,11 @@ enum class Variable : int
     enthalpy_of_evaporation,
     equivalent_plastic_strain,
     grain_compressibility,
+    liquid_phase_pressure,
     liquid_saturation,
     mechanical_strain,
     molar_mass,
+    molar_fraction,
     phase_pressure,
     porosity,
     solid_grain_pressure,
@@ -62,6 +64,7 @@ enum class Variable : int
     total_strain,
     total_stress,
     transport_porosity,
+    vapour_pressure,
     volumetric_strain,
     number_of_variables
 };