diff --git a/source/sparse_matrix.h b/source/sparse_matrix.h
index 63365826..33bdf843 100644
--- a/source/sparse_matrix.h
+++ b/source/sparse_matrix.h
@@ -27,7 +27,7 @@ namespace ryujin
   template <typename Number,
             int n_comp,
             int simd_length,
-            typename MemorySpace = dealii::MemorySpace::Host::kokkos_space,
+            typename MemorySpace = dealii::MemorySpace::Host,
             bool writable = true>
   class SparseMatrixView;
 
@@ -54,7 +54,7 @@ namespace ryujin
     /**
      * Default constructor.
      */
-    SparseMatrix();
+    SparseMatrix() = default;
 
     /**
      * Constructor taking a SIMD sparsity pattern as an argument.
@@ -82,14 +82,14 @@ namespace ryujin
      * Return a writable view on the sparse matrix for the selected memory
      * space.
      */
-    template <typename MemorySpace = dealii::MemorySpace::Host::kokkos_space>
+    template <typename MemorySpace = dealii::MemorySpace::Host>
     SparseMatrixView<Number, n_comp, simd_length, MemorySpace, true> get_view();
 
     /**
      * Return a read-only view on the sparse matrix for the selected memory
      * space.
      */
-    template <typename MemorySpace = dealii::MemorySpace::Host::kokkos_space>
+    template <typename MemorySpace = dealii::MemorySpace::Host>
     SparseMatrixView<Number, n_comp, simd_length, MemorySpace, false>
     get_view() const;
 
@@ -144,15 +144,15 @@ namespace ryujin
     const SparsityPattern<simd_length> *sparsity_pattern_ =
         nullptr; // FIXME shared_ptr
 
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    Kokkos::View<Number *, HostSpace> data_host_;
-    Kokkos::View<Number *, HostSpace> exchange_buffer_host_;
+    using KokkosHost = dealii::MemorySpace::Host::kokkos_space;
+    Kokkos::View<Number *, KokkosHost> data_host_;
+    Kokkos::View<Number *, KokkosHost> exchange_buffer_host_;
 
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
-    Kokkos::View<Number *, DefaultSpace> data_default_;
-    Kokkos::View<Number *, DefaultSpace> exchange_buffer_default_;
+    using KokkosDefault = dealii::MemorySpace::Default::kokkos_space;
+    Kokkos::View<Number *, KokkosDefault> data_default_;
+    Kokkos::View<Number *, KokkosDefault> exchange_buffer_default_;
 
-    bool host_space_active_;
+    bool host_space_active_ = true;
 
     std::vector<MPI_Request> requests_;
 
@@ -359,8 +359,11 @@ namespace ryujin
   private:
     using SM = SparseMatrix<Number, n_comp, simd_length>;
     std::conditional_t<writable, SM *, const SM *> sparse_matrix_;
+
     SparsityPatternView<simd_length, MemorySpace> sparsity_pattern_;
-    Kokkos::View<Number *, MemorySpace> data_;
+
+    using KokkosSpace = typename MemorySpace::kokkos_space;
+    Kokkos::View<Number *, KokkosSpace> data_;
   };
 
 
@@ -412,14 +415,6 @@ namespace ryujin
    */
 
 
-  template <typename Number, int n_components, int simd_length>
-  SparseMatrix<Number, n_components, simd_length>::SparseMatrix()
-      : sparsity_pattern_(nullptr)
-      , host_space_active_(true)
-  {
-  }
-
-
   template <typename Number, int n_components, int simd_length>
   SparseMatrix<Number, n_components, simd_length>::SparseMatrix(
       const SparsityPattern<simd_length> &sparsity)
@@ -435,23 +430,23 @@ namespace ryujin
     this->sparsity_pattern_ = &sparsity;
     this->host_space_active_ = true;
 
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using KokkosHost = dealii::MemorySpace::Host::kokkos_space;
+    using KokkosDefault = dealii::MemorySpace::Default::kokkos_space;
     using Aligned = Kokkos::MemoryTraits<Kokkos::Aligned>;
 
-    data_host_ = Kokkos::View<Number *, HostSpace, Aligned>(
+    data_host_ = Kokkos::View<Number *, KokkosHost, Aligned>(
         "sparse_matrix_data", sparsity.n_nonzero_elements() * n_components);
 
     data_default_ = Kokkos::create_mirror_view(
-        typename DefaultSpace::execution_space(), data_host_);
+        typename KokkosDefault::execution_space(), data_host_);
 
     const std::size_t n_indices = sparsity.entries_to_be_sent().size();
 
-    exchange_buffer_host_ = Kokkos::View<Number *, HostSpace, Aligned>(
+    exchange_buffer_host_ = Kokkos::View<Number *, KokkosHost, Aligned>(
         "sparse_matrix_exchange_buffer", n_components * n_indices);
 
     exchange_buffer_default_ = Kokkos::create_mirror_view(
-        typename DefaultSpace::execution_space(), exchange_buffer_host_);
+        typename KokkosDefault::execution_space(), exchange_buffer_host_);
 
     /* reinitialize the view: */
     SparseMatrixView<Number, n_components, simd_length>::reinit(*this);
@@ -489,11 +484,11 @@ namespace ryujin
   bool SparseMatrix<Number, n_components, simd_length>::is_active_memory_space()
       const
   {
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using HostSpace = dealii::MemorySpace::Host;
+    using DefaultSpace = dealii::MemorySpace::Default;
     static_assert(std::is_same_v<MemorySpace, HostSpace> ||
                       std::is_same_v<MemorySpace, DefaultSpace>,
-                  "Unexpected Kokkos memory space");
+                  "Unexpected memory space");
 
     return host_space_active_ == std::is_same_v<MemorySpace, HostSpace>;
   }
@@ -503,26 +498,33 @@ namespace ryujin
   template <typename MemorySpace>
   void SparseMatrix<Number, n_components, simd_length>::move_to_memory_space()
   {
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using HostSpace = dealii::MemorySpace::Host;
+    using DefaultSpace = dealii::MemorySpace::Default;
     static_assert(std::is_same_v<MemorySpace, HostSpace> ||
                       std::is_same_v<MemorySpace, DefaultSpace>,
-                  "Unexpected Kokkos memory space");
+                  "Unexpected memory space");
 
     if (is_active_memory_space<MemorySpace>())
       return;
 
+    /* No copy required if default and host are the same memory spaces: */
+    constexpr bool move_required =
+        !std::is_same_v<HostSpace::kokkos_space, DefaultSpace::kokkos_space>;
+
     if constexpr (std::is_same_v<MemorySpace, HostSpace>) {
       host_space_active_ = true;
-      Kokkos::deep_copy(/*dst*/ data_host_, /*src*/ data_default_);
-      Kokkos::deep_copy(/*dst*/ exchange_buffer_host_,
-                        /*src*/ exchange_buffer_default_);
-
+      if constexpr (move_required) {
+        Kokkos::deep_copy(/*dst*/ data_host_, /*src*/ data_default_);
+        Kokkos::deep_copy(/*dst*/ exchange_buffer_host_,
+                          /*src*/ exchange_buffer_default_);
+      }
     } else if constexpr (std::is_same_v<MemorySpace, DefaultSpace>) {
       host_space_active_ = false;
-      Kokkos::deep_copy(/*dst*/ data_default_, /*src*/ data_host_);
-      Kokkos::deep_copy(/*dst*/ exchange_buffer_default_,
-                        /*src*/ exchange_buffer_host_);
+      if constexpr (move_required) {
+        Kokkos::deep_copy(/*dst*/ data_default_, /*src*/ data_host_);
+        Kokkos::deep_copy(/*dst*/ exchange_buffer_default_,
+                          /*src*/ exchange_buffer_host_);
+      }
     }
   }
 
@@ -532,8 +534,8 @@ namespace ryujin
   void SparseMatrix<Number, n_components, simd_length>::
       zero_out_ghost_rows_on_memory_space()
   {
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using HostSpace = dealii::MemorySpace::Host;
+    using DefaultSpace = dealii::MemorySpace::Default;
 
     Assert(is_active_memory_space<MemorySpace>(),
            dealii::ExcMessage("The chosen memory space is not active."));
@@ -556,8 +558,8 @@ namespace ryujin
   void SparseMatrix<Number, n_components, simd_length>::
       update_ghost_rows_on_memory_space()
   {
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using HostSpace = dealii::MemorySpace::Host;
+    using DefaultSpace = dealii::MemorySpace::Default;
 
     AssertThrow((std::is_same_v<MemorySpace, HostSpace>),
                 dealii::ExcNotImplemented());
@@ -661,8 +663,8 @@ namespace ryujin
     AssertThrow(operation == dealii::VectorOperation::add,
                 dealii::ExcNotImplemented());
 
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using HostSpace = dealii::MemorySpace::Host;
+    using DefaultSpace = dealii::MemorySpace::Default;
 
     AssertThrow((std::is_same_v<MemorySpace, HostSpace>),
                 dealii::ExcNotImplemented());
@@ -809,8 +811,8 @@ namespace ryujin
       SparseMatrix &sparse_matrix)
     requires(writable != std::is_const_v<SparseMatrix>)
   {
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using HostSpace = dealii::MemorySpace::Host;
+    using DefaultSpace = dealii::MemorySpace::Default;
 
     static_assert(std::is_same_v<MemorySpace, HostSpace> ||
                       std::is_same_v<MemorySpace, DefaultSpace>,
@@ -1162,8 +1164,8 @@ namespace ryujin
       zero_out_ghost_rows() const
     requires(writable)
   {
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using HostSpace = dealii::MemorySpace::Host;
+    using DefaultSpace = dealii::MemorySpace::Default;
 
     static_assert(std::is_same_v<MemorySpace, HostSpace> ||
                       std::is_same_v<MemorySpace, DefaultSpace>,
@@ -1185,8 +1187,8 @@ namespace ryujin
       update_ghost_rows() const
     requires(writable)
   {
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using HostSpace = dealii::MemorySpace::Host;
+    using DefaultSpace = dealii::MemorySpace::Default;
 
     static_assert(std::is_same_v<MemorySpace, HostSpace> ||
                       std::is_same_v<MemorySpace, DefaultSpace>,
@@ -1208,8 +1210,8 @@ namespace ryujin
       compress(dealii::VectorOperation::values operation) const
     requires(writable)
   {
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using HostSpace = dealii::MemorySpace::Host;
+    using DefaultSpace = dealii::MemorySpace::Default;
 
     static_assert(std::is_same_v<MemorySpace, HostSpace> ||
                       std::is_same_v<MemorySpace, DefaultSpace>,
diff --git a/source/sparsity_pattern.h b/source/sparsity_pattern.h
index 89b9d1c1..ddae576f 100644
--- a/source/sparsity_pattern.h
+++ b/source/sparsity_pattern.h
@@ -15,8 +15,7 @@
 
 namespace ryujin
 {
-  template <int simd_length,
-            typename MemorySpace = dealii::MemorySpace::Host::kokkos_space>
+  template <int simd_length, typename MemorySpace = dealii::MemorySpace::Host>
   class SparsityPatternView;
 
 
@@ -132,15 +131,15 @@ namespace ryujin
     unsigned int n_internal_dofs_;
     unsigned int n_locally_owned_dofs_;
 
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    Kokkos::View<unsigned int *, HostSpace> row_starts_host_;
-    Kokkos::View<unsigned int *, HostSpace> column_indices_host_;
-    Kokkos::View<unsigned int *, HostSpace> indices_transposed_host_;
+    using KokkosHost = dealii::MemorySpace::Host::kokkos_space;
+    Kokkos::View<unsigned int *, KokkosHost> row_starts_host_;
+    Kokkos::View<unsigned int *, KokkosHost> column_indices_host_;
+    Kokkos::View<unsigned int *, KokkosHost> indices_transposed_host_;
 
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
-    Kokkos::View<unsigned int *, DefaultSpace> row_starts_default_;
-    Kokkos::View<unsigned int *, DefaultSpace> column_indices_default_;
-    Kokkos::View<unsigned int *, DefaultSpace> indices_transposed_default_;
+    using KokkosDefault = dealii::MemorySpace::Default::kokkos_space;
+    Kokkos::View<unsigned int *, KokkosDefault> row_starts_default_;
+    Kokkos::View<unsigned int *, KokkosDefault> column_indices_default_;
+    Kokkos::View<unsigned int *, KokkosDefault> indices_transposed_default_;
 
     std::vector<std::pair<unsigned int, unsigned int>> entries_to_be_sent_;
     std::vector<std::pair<unsigned int, unsigned int>> send_targets_;
@@ -327,9 +326,10 @@ namespace ryujin
     unsigned int n_internal_dofs_;
     unsigned int n_locally_owned_dofs_;
 
-    Kokkos::View<const unsigned int *, MemorySpace> row_starts_;
-    Kokkos::View<const unsigned int *, MemorySpace> column_indices_;
-    Kokkos::View<const unsigned int *, MemorySpace> indices_transposed_;
+    using KokkosSpace = typename MemorySpace::kokkos_space;
+    Kokkos::View<const unsigned int *, KokkosSpace> row_starts_;
+    Kokkos::View<const unsigned int *, KokkosSpace> column_indices_;
+    Kokkos::View<const unsigned int *, KokkosSpace> indices_transposed_;
     //@}
   };
 
@@ -366,12 +366,12 @@ namespace ryujin
     n_internal_dofs_ = sparsity_pattern.n_internal_dofs_;
     n_locally_owned_dofs_ = sparsity_pattern.n_locally_owned_dofs_;
 
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using HostSpace = dealii::MemorySpace::Host;
+    using DefaultSpace = dealii::MemorySpace::Default;
 
     static_assert(std::is_same_v<MemorySpace, HostSpace> ||
                       std::is_same_v<MemorySpace, DefaultSpace>,
-                  "Unexpected Kokkos memory space");
+                  "Unexpected memory space");
 
     if constexpr (std::is_same_v<MemorySpace, HostSpace>) {
       row_starts_ = sparsity_pattern.row_starts_host_;
diff --git a/source/sparsity_pattern.template.h b/source/sparsity_pattern.template.h
index 14726e35..983526bd 100644
--- a/source/sparsity_pattern.template.h
+++ b/source/sparsity_pattern.template.h
@@ -86,19 +86,19 @@ namespace ryujin
 
     /* Allocate memory: */
 
-    using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-    using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+    using KokkosHost = dealii::MemorySpace::Host::kokkos_space;
+    using KokkosDefault = dealii::MemorySpace::Default::kokkos_space;
     using Aligned = Kokkos::MemoryTraits<Kokkos::Aligned>;
 
-    row_starts_host_ = Kokkos::View<unsigned int *, HostSpace, Aligned>(
+    row_starts_host_ = Kokkos::View<unsigned int *, KokkosHost, Aligned>(
         "sparsity_pattern_row_starts", sparsity.n_rows() + 1);
 
-    column_indices_host_ = Kokkos::View<unsigned int *, HostSpace, Aligned>(
-        "sparsity_pattern_column_indices", sparsity.n_nonzero_elements());
-
-    indices_transposed_host_ = Kokkos::View<unsigned int *, HostSpace, Aligned>(
+    column_indices_host_ = Kokkos::View<unsigned int *, KokkosHost, Aligned>(
         "sparsity_pattern_column_indices", sparsity.n_nonzero_elements());
 
+    indices_transposed_host_ =
+        Kokkos::View<unsigned int *, KokkosHost, Aligned>(
+            "sparsity_pattern_column_indices", sparsity.n_nonzero_elements());
 
     /* Vectorized part: */
 
@@ -390,13 +390,13 @@ namespace ryujin
      */
 
     row_starts_default_ = Kokkos::create_mirror_view_and_copy(
-        typename DefaultSpace::execution_space(), row_starts_host_);
+        typename KokkosDefault::execution_space(), row_starts_host_);
 
     column_indices_default_ = Kokkos::create_mirror_view_and_copy(
-        typename DefaultSpace::execution_space(), column_indices_host_);
+        typename KokkosDefault::execution_space(), column_indices_host_);
 
     indices_transposed_default_ = Kokkos::create_mirror_view_and_copy(
-        typename DefaultSpace::execution_space(), indices_transposed_host_);
+        typename KokkosDefault::execution_space(), indices_transposed_host_);
 
     SparsityPatternView<simd_length>::reinit(*this);
   }
diff --git a/tests/common/sparse_matrix_02.cc b/tests/common/sparse_matrix_02.cc
index bad7f515..75bb60e1 100644
--- a/tests/common/sparse_matrix_02.cc
+++ b/tests/common/sparse_matrix_02.cc
@@ -36,8 +36,8 @@ int main(int argc, char *argv[])
   ryujin::SparseMatrix<double, 1, simd_width> sparse_matrix;
   sparse_matrix.reinit(sparsity_pattern);
 
-  using HostSpace = dealii::MemorySpace::Host::kokkos_space;
-  using DefaultSpace = dealii::MemorySpace::Default::kokkos_space;
+  using HostSpace = dealii::MemorySpace::Host;
+  using DefaultSpace = dealii::MemorySpace::Default;
 
   const auto print_status = [&]() {
     std::cout << "HostSpace active == "
@@ -67,7 +67,7 @@ int main(int argc, char *argv[])
   print_status();
 
   const auto &view = sparse_matrix.template get_view<DefaultSpace>();
-  using ExecutionSpace = DefaultSpace::execution_space;
+  using ExecutionSpace = DefaultSpace::kokkos_space::execution_space;
   const auto exec = ExecutionSpace{};
   Kokkos::parallel_for("test",
                        Kokkos::RangePolicy<ExecutionSpace>(exec, 0, 3),
diff --git a/tests/common/sparse_matrix_02.threads=2.output b/tests/common/sparse_matrix_02.threads=2.output
index 106cb45b..6392a299 100644
--- a/tests/common/sparse_matrix_02.threads=2.output
+++ b/tests/common/sparse_matrix_02.threads=2.output
@@ -1,14 +1,14 @@
 HostSpace active == 1
-DefaultSpace active == 1
+DefaultSpace active == 0
 After move to DefaultSpace:
-HostSpace active == 1
+HostSpace active == 0
 DefaultSpace active == 1
 After repeated move to DefaultSpace:
-HostSpace active == 1
+HostSpace active == 0
 DefaultSpace active == 1
 After move to HostSpace:
 HostSpace active == 1
-DefaultSpace active == 1
+DefaultSpace active == 0
 Entry (0, 0): 42
 Entry (1, 1): 420
 Entry (2, 2): 4200
diff --git a/tests/common/sparse_matrix_02.threads=2.output.cuda b/tests/common/sparse_matrix_02.threads=2.output.cuda
deleted file mode 100644
index 6392a299..00000000
--- a/tests/common/sparse_matrix_02.threads=2.output.cuda
+++ /dev/null
@@ -1,14 +0,0 @@
-HostSpace active == 1
-DefaultSpace active == 0
-After move to DefaultSpace:
-HostSpace active == 0
-DefaultSpace active == 1
-After repeated move to DefaultSpace:
-HostSpace active == 0
-DefaultSpace active == 1
-After move to HostSpace:
-HostSpace active == 1
-DefaultSpace active == 0
-Entry (0, 0): 42
-Entry (1, 1): 420
-Entry (2, 2): 4200