diff --git a/Lib/test/test_re.py b/Lib/test/test_re.py
index 0b710e3766..dac18cc268 100644
--- a/Lib/test/test_re.py
+++ b/Lib/test/test_re.py
@@ -1516,8 +1516,17 @@ class ReTests(unittest.TestCase):
         self.assertRaises(re.error, re.compile, r'(?au)\w')
 
     def test_locale_flag(self):
-        import locale
-        _, enc = locale.getlocale(locale.LC_CTYPE)
+        # On Windows, Python doesn't set LC_CTYPE to the user preferred
+        # locale and so LC_CTYPE is the C locale which is different than
+        # the ANSI code page returned by getpreferredencoding().
+        # Set temporarily the LC_CTYPE locale to the user preferred locale
+        # to get the correct encoding name.
+        oldloc = locale.setlocale(locale.LC_CTYPE, None)
+        locale.setlocale(locale.LC_CTYPE, "")
+        self.addCleanup(locale.setlocale, locale.LC_CTYPE, oldloc)
+
+        enc = locale.getpreferredencoding()
+
         # Search non-ASCII letter
         for i in range(128, 256):
             try:
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index eb050ff112..b5c54e3c7f 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -4576,6 +4576,47 @@ get_main_config(PyObject *self, PyObject *Py_UNUSED(args))
 }
 
 
+static unsigned int sre_lower_ascii(unsigned int ch)
+{
+    return ((ch) < 128 ? Py_TOLOWER(ch) : ch);
+}
+
+static unsigned int sre_upper_ascii(unsigned int ch)
+{
+    return ((ch) < 128 ? Py_TOUPPER(ch) : ch);
+}
+
+static PyObject *
+victor2(unsigned int ch)
+{
+    char str[2];
+    str[0] = (char)ch;
+    str[1] = 0;
+    wchar_t wstr[2];
+    memset(wstr, 0, sizeof(wstr));
+
+    size_t res = mbstowcs(wstr, str, 1);
+    if (res == (size_t)-1) {
+        return PyUnicode_FromString("<ERR>");
+    }
+    return PyUnicode_FromWideChar(wstr, 1);
+}
+
+static PyObject *
+victor(PyObject *self, PyObject *args)
+{
+    unsigned int ch;
+    if (!PyArg_ParseTuple(args, "I", &ch)) {
+        return NULL;
+    }
+    unsigned int up = sre_upper_ascii(ch);
+    unsigned int low = sre_lower_ascii(ch);
+    return Py_BuildValue("(NNNNN)",
+        PyLong_FromUnsignedLong(up), PyLong_FromUnsignedLong(low),
+        victor2(ch), victor2(up), victor2(low));
+}
+
+
 static PyMethodDef TestMethods[] = {
     {"raise_exception",         raise_exception,                 METH_VARARGS},
     {"raise_memoryerror",   (PyCFunction)raise_memoryerror,  METH_NOARGS},
@@ -4805,6 +4846,7 @@ static PyMethodDef TestMethods[] = {
     {"get_global_config", get_global_config, METH_NOARGS},
     {"get_core_config", get_core_config, METH_NOARGS},
     {"get_main_config", get_main_config, METH_NOARGS},
+    {"victor", victor, METH_VARARGS},
     {NULL, NULL} /* sentinel */
 };