diff --git a/core/test/utils.hpp b/core/test/utils.hpp
index 89b135a01f3..4f38565c1da 100644
--- a/core/test/utils.hpp
+++ b/core/test/utils.hpp
@@ -39,6 +39,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <type_traits>
 
 
+#include <gtest/gtest.h>
+
+
 #include <ginkgo/core/base/math.hpp>
 #include <ginkgo/core/base/types.hpp>
 
@@ -51,46 +54,50 @@ namespace gko {
 namespace test {
 
 
-using ValueTypes =
-    ::testing::Types<float, double, std::complex<float>, std::complex<double>>;
+typedef ::testing::Types<float, double, std::complex<float>,
+                         std::complex<double>>
+    ValueTypes;
 
 
-using ComplexValueTypes =
-    ::testing::Types<std::complex<float>, std::complex<double>>;
+typedef ::testing::Types<std::complex<float>, std::complex<double>>
+    ComplexValueTypes;
 
 
-using IndexTypes = ::testing::Types<gko::int32, gko::int64>;
+typedef ::testing::Types<gko::int32, gko::int64> IndexTypes;
 
 
-using ValueAndIndexTypes =
-    ::testing::Types<float, double, std::complex<float>, std::complex<double>,
-                     gko::int32, gko::int64, gko::size_type>;
+typedef ::testing::Types<float, double, std::complex<float>,
+                         std::complex<double>, gko::int32, gko::int64,
+                         gko::size_type>
+    ValueAndIndexTypes;
 
 
-using ValueIndexTypes = ::testing::Types<
+typedef ::testing::Types<
     std::tuple<float, gko::int32>, std::tuple<double, gko::int32>,
     std::tuple<std::complex<float>, gko::int32>,
     std::tuple<std::complex<double>, gko::int32>, std::tuple<float, gko::int64>,
     std::tuple<double, gko::int64>, std::tuple<std::complex<float>, gko::int64>,
-    std::tuple<std::complex<double>, gko::int64>>;
+    std::tuple<std::complex<double>, gko::int64>>
+    ValueIndexTypes;
 
 
-using RealValueIndexTypes = ::testing::Types<
+typedef ::testing::Types<
     std::tuple<float, gko::int32>, std::tuple<double, gko::int32>,
-    std::tuple<float, gko::int64>, std::tuple<double, gko::int64>>;
+    std::tuple<float, gko::int64>, std::tuple<double, gko::int64>>
+    RealValueIndexTypes;
 
 
-using ComplexValueIndexTypes =
-    ::testing::Types<std::tuple<std::complex<float>, gko::int32>,
-                     std::tuple<std::complex<double>, gko::int32>,
-                     std::tuple<std::complex<float>, gko::int64>,
-                     std::tuple<std::complex<double>, gko::int64>>;
+typedef ::testing::Types<std::tuple<std::complex<float>, gko::int32>,
+                         std::tuple<std::complex<double>, gko::int32>,
+                         std::tuple<std::complex<float>, gko::int64>,
+                         std::tuple<std::complex<double>, gko::int64>>
+    ComplexValueIndexTypes;
 
 
 template <typename T>
 struct reduction_factor {
     static constexpr gko::remove_complex<T> value =
-        std::is_same<gko::remove_complex<T>, float>::value ? 1.0e-7 : 1.0e-14;
+        std::is_same<gko::remove_complex<T>, float>::value ? 1.0e-7f : 1.0e-14;
 };
 
 
diff --git a/include/ginkgo/core/base/executor.hpp b/include/ginkgo/core/base/executor.hpp
index e369c031d07..0f4c1ad07c3 100644
--- a/include/ginkgo/core/base/executor.hpp
+++ b/include/ginkgo/core/base/executor.hpp
@@ -569,7 +569,7 @@ class Executor : public log::EnableLogging<Executor> {
         try {
             this->raw_copy_from(src_exec, num_elems * sizeof(T), src_ptr,
                                 dest_ptr);
-        } catch (NotSupported &err) {
+        } catch (NotSupported &) {
             // Unoptimized copy. Try to go through the masters.
             auto src_master = src_exec->get_master().get();
             if (num_elems > 0 && src_master != src_exec) {
diff --git a/include/ginkgo/core/base/lin_op.hpp b/include/ginkgo/core/base/lin_op.hpp
index 6c873198b6e..a49d945d1ca 100644
--- a/include/ginkgo/core/base/lin_op.hpp
+++ b/include/ginkgo/core/base/lin_op.hpp
@@ -810,12 +810,12 @@ using EnableDefaultLinOpFactory =
  *
  * @ingroup LinOp
  */
-#define GKO_CREATE_FACTORY_PARAMETERS(_parameters_name, _factory_name) \
-public:                                                                \
-    class _factory_name;                                               \
-    struct _parameters_name##_type                                     \
-        : ::gko::enable_parameters_type<_parameters_name##_type,       \
-                                        _factory_name>
+#define GKO_CREATE_FACTORY_PARAMETERS(_parameters_name, _factory_name)  \
+public:                                                                 \
+    class _factory_name;                                                \
+    class _parameters_name##_type                                       \
+        : public ::gko::enable_parameters_type<_parameters_name##_type, \
+                                               _factory_name>
 
 
 /**
diff --git a/include/ginkgo/core/matrix/csr.hpp b/include/ginkgo/core/matrix/csr.hpp
index a30f6f856e3..bc83a6be795 100644
--- a/include/ginkgo/core/matrix/csr.hpp
+++ b/include/ginkgo/core/matrix/csr.hpp
@@ -484,13 +484,13 @@ class Csr : public EnableLinOp<Csr<ValueType, IndexType>>,
         const index_type nvidia_row_len_limit = 1024;
         /* Use imbalance strategy when the matrix has more more than 1e6 on
          * NVIDIA hardware */
-        const index_type nvidia_nnz_limit = 1e6;
+        const index_type nvidia_nnz_limit{1e6};
         /* Use imbalance strategy when the maximum number of nonzero per row is
          * more than 768 on AMD hardware */
         const index_type amd_row_len_limit = 768;
         /* Use imbalance strategy when the matrix has more more than 1e8 on AMD
          * hardware */
-        const index_type amd_nnz_limit = 1e8;
+        const index_type amd_nnz_limit{1e8};
 
         /**
          * Creates an automatical strategy.
diff --git a/third_party/gtest/CMakeLists.txt b/third_party/gtest/CMakeLists.txt
index f68db6d2060..9d13c970cc7 100644
--- a/third_party/gtest/CMakeLists.txt
+++ b/third_party/gtest/CMakeLists.txt
@@ -2,13 +2,13 @@ if(MSVC)
     # Force using shared runtime library when MSVC builds shared libraries
     ginkgo_load_git_package(gtest_external
         "https://github.com/google/googletest.git"
-        "ee3aa831172090fd5442820f215cb04ab6062756"
+        "6a7ed316a5cdc07b6d26362c90770787513822d4"
         # Work around the linking errors when compiling gtest with CUDA
         "-Dgtest_disable_pthreads=ON" "-Dgtest_force_shared_crt=${BUILD_SHARED_LIBS}")
 else()
     ginkgo_load_git_package(gtest_external
         "https://github.com/google/googletest.git"
-        "ee3aa831172090fd5442820f215cb04ab6062756"
+        "6a7ed316a5cdc07b6d26362c90770787513822d4"
         # Work around the linking errors when compiling gtest with CUDA
         "-Dgtest_disable_pthreads=ON"
         "-DCMAKE_CXX_FLAGS=-fPIC")