diff --git a/ProcessLib/ThermalTwoPhaseFlowWithPP/CreateThermalTwoPhaseFlowWithPPProcess.cpp b/ProcessLib/ThermalTwoPhaseFlowWithPP/CreateThermalTwoPhaseFlowWithPPProcess.cpp
index c0a1ad1264435c9848b47364dc3f0977b65b1677..167924cf33a762e8b0a4131b124dec5459b5bbd9 100644
--- a/ProcessLib/ThermalTwoPhaseFlowWithPP/CreateThermalTwoPhaseFlowWithPPProcess.cpp
+++ b/ProcessLib/ThermalTwoPhaseFlowWithPP/CreateThermalTwoPhaseFlowWithPPProcess.cpp
@@ -90,12 +90,6 @@ std::unique_ptr<Process> createThermalTwoPhaseFlowWithPPProcess(
 
     // Parameter for the density of the solid.
 
-    auto const& density_solid = ParameterLib::findParameter<double>(
-        config,
-        //! \ogs_file_param_special{prj__processes__process__TWOPHASE_FLOW_THERMAL__density_solid}
-        "density_solid", parameters, 1, &mesh);
-    DBUG("Use '{:s}' as density_solid parameter.", density_solid.name);
-
     // Parameter for the latent heat of evaporation.
     auto const& latent_heat_evaporation = ParameterLib::findParameter<double>(
         config,
@@ -114,12 +108,14 @@ std::unique_ptr<Process> createThermalTwoPhaseFlowWithPPProcess(
     auto media_map =
         MaterialPropertyLib::createMaterialSpatialDistributionMap(media, mesh);
 
-    ThermalTwoPhaseFlowWithPPProcessData process_data{
-        std::move(media_map), specific_body_force,
-        has_gravity,          mass_lumping,
-        diff_coeff_b,         diff_coeff_a,
-        density_solid,        latent_heat_evaporation,
-        std::move(material)};
+    ThermalTwoPhaseFlowWithPPProcessData process_data{std::move(media_map),
+                                                      specific_body_force,
+                                                      has_gravity,
+                                                      mass_lumping,
+                                                      diff_coeff_b,
+                                                      diff_coeff_a,
+                                                      latent_heat_evaporation,
+                                                      std::move(material)};
 
     return std::make_unique<ThermalTwoPhaseFlowWithPPProcess>(
         std::move(name), mesh, std::move(jacobian_assembler), parameters,
diff --git a/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPLocalAssembler-impl.h b/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPLocalAssembler-impl.h
index f28f2f64bc63fee179d341e77e3358e2a4f8b03d..d0d61c312dd4ebfd8aee8654a66c46dc7e5e9209 100644
--- a/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPLocalAssembler-impl.h
+++ b/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPLocalAssembler-impl.h
@@ -182,6 +182,7 @@ void ThermalTwoPhaseFlowWithPPLocalAssembler<
         auto const& medium =
             *_process_data.media_map->getMedium(this->_element.getID());
         auto const& liquid_phase = medium.phase("AqueousLiquid");
+        auto const& solid_phase = medium.phase("Solid");
 
         auto const density_water =
             liquid_phase.property(MaterialPropertyLib::PropertyType::density)
@@ -235,7 +236,9 @@ void ThermalTwoPhaseFlowWithPPLocalAssembler<
             p_vapor_nonwet * water_mol_mass / IdealGasConstant / T_int_pt;
         double const density_nonwet = density_nonwet_gas + density_nonwet_vapor;
         double const density_wet = density_water;
-        double const density_solid = _process_data.density_solid(t, pos)[0];
+        auto const density_solid =
+            solid_phase.property(MaterialPropertyLib::PropertyType::density)
+                .template value<double>(vars, pos, t, dt);
         // Derivative of nonwet phase density in terms of T
         double const d_density_nonwet_d_T =
             _process_data.material->calculatedDensityNonwetdT (
diff --git a/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPProcessData.h b/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPProcessData.h
index 448adf2ecb6bbfc5ef32a6b309a9b3b6a0e3832d..349fa5b603c80a27e60ef6be2986019eea0d9463 100644
--- a/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPProcessData.h
+++ b/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPProcessData.h
@@ -30,7 +30,6 @@ struct ThermalTwoPhaseFlowWithPPProcessData
     bool const has_mass_lumping;
     ParameterLib::Parameter<double> const& diffusion_coeff_component_b;
     ParameterLib::Parameter<double> const& diffusion_coeff_component_a;
-    ParameterLib::Parameter<double> const& density_solid;
     ParameterLib::Parameter<double> const& latent_heat_evaporation;
     std::unique_ptr<ThermalTwoPhaseFlowWithPPMaterialProperties> material;
 };