diff --git a/dumux/boxmodels/common/boxpropertydefaults.hh b/dumux/boxmodels/common/boxpropertydefaults.hh
index 98217a17ae08545e2a811b17a5b9689fa44d96e8..841b486b6ca1bb6a868ce2d8a28ec33e2559facd 100644
--- a/dumux/boxmodels/common/boxpropertydefaults.hh
+++ b/dumux/boxmodels/common/boxpropertydefaults.hh
@@ -218,6 +218,13 @@ SET_PROP(BoxModel, LSMaxIterations)
 {public:
     static constexpr int value = 250;
 };
+
+//! set number of equations of the mathematical model as default
+SET_PROP_DEFAULT(LSBlockSize)
+{public:
+    static constexpr int value = GET_PROP_VALUE(TypeTag, PTAG(NumEq));
+};
+
 } // namespace Properties
 } // namespace Dumux
 
diff --git a/dumux/decoupled/common/decoupledproperties.hh b/dumux/decoupled/common/decoupledproperties.hh
index 6256ab81f2b51d659e0f9ae033d794370d4f44cf..4931f9c0d25111c10dd4cb3805edc4a8654dddeb 100644
--- a/dumux/decoupled/common/decoupledproperties.hh
+++ b/dumux/decoupled/common/decoupledproperties.hh
@@ -53,6 +53,7 @@ NEW_TYPE_TAG(DecoupledModel, INHERITS_FROM(ExplicitModel, LinearSolverTypeTag));
 //! grid, and elements, and shape functions.
 NEW_PROP_TAG( SolutionTypes);
 NEW_PROP_TAG( TransportSolutionType);
+NEW_PROP_TAG( PrimaryVariables);
 
 NEW_PROP_TAG( Grid); //!< The type of the DUNE grid
 NEW_PROP_TAG( GridView); //!< The type of the grid view
@@ -163,6 +164,8 @@ public:
     typedef Dune::BlockVector<Dune::FieldVector<Dune::FieldVector<Scalar, dim>, 2*dim > > DimVecElemFace;//!<type for vector of vectors (of size 2 x dimension) of vector (of size dimension) of scalars
 };
 
+SET_TYPE_PROP(DecoupledModel,  PrimaryVariables, typename GET_PROP(TypeTag, PTAG(SolutionTypes))::PrimaryVariables);
+
 /*!
  * \brief Default implementation for the Vector of the transportet quantity
  *
@@ -203,6 +206,12 @@ SET_PROP(DecoupledModel, LSMaxIterations)
 {public:
     static constexpr int value = 500;
 };
+
+//! set the default number of maximum iterations for the linear solver
+SET_PROP(DecoupledModel, LSBlockSize)
+{public:
+    static constexpr int value = 1;
+};
 // \}
 
 }
diff --git a/dumux/linear/linearsolverproperties.hh b/dumux/linear/linearsolverproperties.hh
index 2606805aba7aef3fa33780e8fa1e4f0cc3b92aad..c39becb3b78b15d826cc2557c85160ef2fff17ef 100644
--- a/dumux/linear/linearsolverproperties.hh
+++ b/dumux/linear/linearsolverproperties.hh
@@ -65,6 +65,15 @@ NEW_PROP_TAG(PreconditionerIterations);
 //! restart parameter for GMRes
 NEW_PROP_TAG(GMResRestart);
 
+//! Size of the matrix/vector blocks
+/*!
+ * The number of different types of equations which build the system of equations to solve
+ * can differ from the number of equations given by the mathematical/physical model (e.g. IMPES).
+ * Thus, the block size does not have to be equal to NumEq.
+ * (Especially important for the SuperLU solver!)
+ */
+NEW_PROP_TAG(LSBlockSize);
+
 //! do not print anything by default
 SET_PROP_DEFAULT(NewtonLinearSolverVerbosity)
 {public:
@@ -92,6 +101,7 @@ SET_PROP_DEFAULT(GMResRestart)
 {public:
     static constexpr int value = 10;
 };
+
 } // namespace Properties
 } // namespace Dumux
 
diff --git a/dumux/linear/seqsolverbackend.hh b/dumux/linear/seqsolverbackend.hh
index 43e27026b52a8450c48380b0b16cf807b6c0a2a8..40c864113515e52ebafc5509713601a9599f56d7 100644
--- a/dumux/linear/seqsolverbackend.hh
+++ b/dumux/linear/seqsolverbackend.hh
@@ -471,8 +471,8 @@ public:
     Vector bTmp(b);
 
     typedef typename GET_PROP_TYPE(TypeTag, PTAG(Scalar)) Scalar;
-    enum {numEq = GET_PROP_VALUE(TypeTag, PTAG(NumEq))};
-    typedef typename Dune::FieldMatrix<Scalar, numEq, numEq> MatrixBlock;
+    enum {blockSize = GET_PROP_VALUE(TypeTag, PTAG(LSBlockSize))};
+    typedef typename Dune::FieldMatrix<Scalar, blockSize, blockSize> MatrixBlock;
     typedef typename Dune::BCRSMatrix<MatrixBlock> ISTLMatrix;
 
     Dune::SuperLU<ISTLMatrix> solver(A);