diff --git a/VTK/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx b/VTK/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx
index deff95758c2bc7c3436431441b1b278f356ff9bb..1e9b6e1214552f4f0c51935f312c544863eb3180 100644
--- a/VTK/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx
+++ b/VTK/Utilities/PythonInterpreter/vtkPythonInterpreter.cxx
@@ -97,6 +97,7 @@ wchar_t* vtk_Py_UTF8ToWide(const char* arg)
   return result;
 }
 
+#if PY_VERSION_HEX < 0x03080000
 std::string vtk_Py_WideToUTF8(const wchar_t* arg)
 {
   std::string result;
@@ -110,6 +111,7 @@ std::string vtk_Py_WideToUTF8(const wchar_t* arg)
 
   return result;
 }
+#endif
 
 std::vector<vtkWeakPointer<vtkPythonInterpreter>>* GlobalInterpreters;
 std::vector<std::string> PythonPaths;
@@ -335,12 +337,21 @@ void SetupPythonPaths(bool isolated, std::string vtklib, const char* landmark)
   if (vtklib.empty())
   {
     VTKPY_DEBUG_MESSAGE(
-      "`GetVTKVersion` library couldn't be found. Will use `Py_GetProgramName` next.");
+      "`GetVTKVersion` library couldn't be found. Will use `sys.executable` next.");
   }
 
   if (vtklib.empty())
   {
+#if PY_VERSION_HEX >= 0x03080000
+    vtkPythonScopeGilEnsurer gilEnsurer;
+    PyObject* executable_path = PySys_GetObject("executable");
+    if (executable_path != Py_None)
+    {
+      vtklib = PyUnicode_AsUTF8AndSize(executable_path, nullptr);
+    }
+#else
     vtklib = vtk_Py_WideToUTF8(Py_GetProgramName());
+#endif
   }
 
   vtklib = systools::CollapseFullPath(vtklib);
diff --git a/VTK/Wrapping/Python/vtkmodules/test/Testing.py b/VTK/Wrapping/Python/vtkmodules/test/Testing.py
index 2891474a6d41e444f449d792dbd2e86ebbdd7520..e0b8675a48b98f8ee113fe7470feaa92aa4566f2 100644
--- a/VTK/Wrapping/Python/vtkmodules/test/Testing.py
+++ b/VTK/Wrapping/Python/vtkmodules/test/Testing.py
@@ -515,8 +515,10 @@ def test(cases):
     """
     # Make the test suites from the arguments.
     suites = []
-    for case in cases:
-        suites.append(unittest.makeSuite(case[0], case[1]))
+    loader = unittest.TestLoader()
+    # the "name" is ignored (it was always just 'test')
+    for test,name in cases:
+        suites.append(loader.loadTestsFromTestCase(test))
     test_suite = unittest.TestSuite(suites)
 
     # Now run the tests.
diff --git a/VTK/Wrapping/PythonCore/PyVTKNamespace.cxx b/VTK/Wrapping/PythonCore/PyVTKNamespace.cxx
index bed60dc47cbeff3daaf4dd22618b11c1abc77334..c1823084086318f566ff388086fc7e040957fab3 100644
--- a/VTK/Wrapping/PythonCore/PyVTKNamespace.cxx
+++ b/VTK/Wrapping/PythonCore/PyVTKNamespace.cxx
@@ -112,8 +112,10 @@ PyObject* PyVTKNamespace_New(const char* name)
   {
     // make sure python has readied the type object
     PyType_Ready(&PyVTKNamespace_Type);
-    // call the allocator provided by python for this type
-    self = PyVTKNamespace_Type.tp_alloc(&PyVTKNamespace_Type, 0);
+    // call the superclass new function
+    PyObject* empty = PyTuple_New(0);
+    self = PyVTKNamespace_Type.tp_base->tp_new(&PyVTKNamespace_Type, empty, nullptr);
+    Py_DECREF(empty);
     // call the superclass init function
     PyObject* pyname = PyUnicode_FromString(name);
     PyObject* args = PyTuple_Pack(1, pyname);
diff --git a/VTK/Wrapping/PythonCore/PyVTKTemplate.cxx b/VTK/Wrapping/PythonCore/PyVTKTemplate.cxx
index 26421f60f07ccece05a98f7f96090f968623902a..e7780bf10076af9fdabe728a31c5968b85ea43ed 100644
--- a/VTK/Wrapping/PythonCore/PyVTKTemplate.cxx
+++ b/VTK/Wrapping/PythonCore/PyVTKTemplate.cxx
@@ -761,8 +761,10 @@ PyObject* PyVTKTemplate_New(const char* name, const char* docstring)
 {
   // make sure python has readied the type object
   PyType_Ready(&PyVTKTemplate_Type);
-  // call the allocator provided by python for this type
-  PyObject* self = PyVTKTemplate_Type.tp_alloc(&PyVTKTemplate_Type, 0);
+  // call the superclass new function
+  PyObject* empty = PyTuple_New(0);
+  PyObject* self = PyVTKTemplate_Type.tp_base->tp_new(&PyVTKTemplate_Type, empty, nullptr);
+  Py_DECREF(empty);
   // call the superclass init function
   PyObject* pyname = PyUnicode_FromString(name);
   PyObject* pydoc = PyUnicode_FromString(docstring);