diff --git a/dumux/material/solidstates/compositionalsolidstate.hh b/dumux/material/solidstates/compositionalsolidstate.hh
index 3621afb101a0849e2a69db1e73f7cdd081a9b117..68a7e0b60ccae8e21a17c3aa1b3dff88b72a8797 100644
--- a/dumux/material/solidstates/compositionalsolidstate.hh
+++ b/dumux/material/solidstates/compositionalsolidstate.hh
@@ -26,26 +26,27 @@
 #ifndef DUMUX_SOLID_STATE_COMPOSITIONAL_HH
 #define DUMUX_SOLID_STATE_COMPOSITIONAL_HH
 
-#include "updatesolidvolumefractions.hh"
-
-namespace Dumux
-{
+namespace Dumux {
 
 /*!
  * \ingroup SolidStates
  * \brief Represents all relevant thermodynamic quantities of a inert
  *        solid system
  */
-template <class Scalar, class SolidSystem>
+template <class Scalar, class SolidSystemType>
 class CompositionalSolidState
 {
 public:
+    using SolidSystem = SolidSystemType;
+
     enum
     {
         numComponents = SolidSystem::numComponents,
         numInertComponents = SolidSystem::numInertComponents,
     };
+
     static constexpr bool isInert() { return SolidSystem::isInert(); }
+
     /*!
      * \brief The average molar mass \f$\overline M_\alpha\f$ of phase \f$\alpha\f$ in \f$\mathrm{[kg/mol]}\f$
      *
diff --git a/dumux/material/solidstates/inertsolidstate.hh b/dumux/material/solidstates/inertsolidstate.hh
index dee1b2e576f3caa603c83005964e7ac14fbc722c..fb86c49c7ce820e77d0d79e3994187ca0d8d2a01 100644
--- a/dumux/material/solidstates/inertsolidstate.hh
+++ b/dumux/material/solidstates/inertsolidstate.hh
@@ -26,25 +26,25 @@
 #ifndef DUMUX_INERT_SOLID_STATE_HH
 #define DUMUX_INERT_SOLID_STATE_HH
 
-#include "updatesolidvolumefractions.hh"
-
-namespace Dumux
-{
+namespace Dumux {
 
 /*!
  * \ingroup SolidStates
  * \brief Represents all relevant thermodynamic quantities of a inert
  *        solid system
  */
-template <class Scalar, class SolidSystem>
+template <class Scalar, class SolidSystemType>
 class InertSolidState
 {
 public:
+    using SolidSystem = SolidSystemType;
+
     enum
     {
         numComponents = SolidSystem::numComponents,
         numInertComponents = SolidSystem::numInertComponents,
     };
+
     static constexpr bool isInert()
     {
         static_assert(SolidSystem::isInert(), "Only inert solid systems are allowed with the InertSolidState");