diff --git a/Lib/_bootlocale.py b/Lib/_bootlocale.py
deleted file mode 100644
--- a/Lib/_bootlocale.py
+++ /dev/null
@@ -1,34 +0,0 @@
-"""A minimal subset of the locale module used at interpreter startup
-(imported by the _io module), in order to reduce startup time.
-
-Don't import directly from third-party code; use the `locale` module instead!
-"""
-
-import sys
-import _locale
-
-if sys.platform.startswith("win"):
-    def getpreferredencoding(do_setlocale=True):
-        return _locale._getdefaultlocale()[1]
-else:
-    try:
-        _locale.CODESET
-    except AttributeError:
-        def getpreferredencoding(do_setlocale=True):
-            # This path for legacy systems needs the more complex
-            # getdefaultlocale() function, import the full locale module.
-            import locale
-            return locale.getpreferredencoding(do_setlocale)
-    else:
-        def getpreferredencoding(do_setlocale=True):
-            assert not do_setlocale
-            result = _locale.nl_langinfo(_locale.CODESET)
-            if not result and sys.platform == 'darwin':
-                # nl_langinfo can return an empty string
-                # when the setting has an invalid value.
-                # Default to UTF-8 in that case because
-                # UTF-8 is the default charset on OSX and
-                # returning nothing will crash the
-                # interpreter.
-                result = 'UTF-8'
-            return result
diff --git a/Lib/locale.py b/Lib/locale.py
--- a/Lib/locale.py
+++ b/Lib/locale.py
@@ -612,8 +612,8 @@ if sys.platform.startswith("win"):
     # On Win32, this will return the ANSI code page
     def getpreferredencoding(do_setlocale = True):
         """Return the charset that the user is likely using."""
-        import _bootlocale
-        return _bootlocale.getpreferredencoding(False)
+        import _locale
+        return _locale._getdefaultlocale()[1]
 else:
     # On Unix, if CODESET is available, use that.
     try:
@@ -632,16 +632,27 @@ else:
         def getpreferredencoding(do_setlocale = True):
             """Return the charset that the user is likely using,
             according to the system configuration."""
-            import _bootlocale
             if do_setlocale:
                 oldloc = setlocale(LC_CTYPE)
                 try:
                     setlocale(LC_CTYPE, "")
                 except Error:
                     pass
-            result = _bootlocale.getpreferredencoding(False)
-            if do_setlocale:
+                result = nl_langinfo(CODESET)
+                if not result and sys.platform == 'darwin':
+                    # nl_langinfo can return an empty string
+                    # when the setting has an invalid value.
+                    # Default to UTF-8 in that case because
+                    # UTF-8 is the default charset on OSX and
+                    # returning nothing will crash the
+                    # interpreter.
+                    result = 'UTF-8'
                 setlocale(LC_CTYPE, oldloc)
+            else:
+                result = nl_langinfo(CODESET)
+                if not result and sys.platform == 'darwin':
+                    # See above for explanation
+                    result = 'UTF-8'
             return result
 
 
diff --git a/Lib/site.py b/Lib/site.py
--- a/Lib/site.py
+++ b/Lib/site.py
@@ -428,8 +428,8 @@ def aliasmbcs():
     while they are always available as "mbcs" in each locale. Make
     them usable by aliasing to "mbcs" in such a case."""
     if sys.platform == 'win32':
-        import _bootlocale, codecs
-        enc = _bootlocale.getpreferredencoding(False)
+        import locale, codecs
+        enc = locale.getdefaultlocale()[1]
         if enc.startswith('cp'):            # "cp***" ?
             try:
                 codecs.lookup(enc)
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -872,9 +872,8 @@ class ProcessTestCase(BaseTestCase):
         #
         # UTF-16 and UTF-32-BE are sufficient to check both with BOM and
         # without, and UTF-16 and UTF-32.
-        import _bootlocale
         for encoding in ['utf-16', 'utf-32-be']:
-            old_getpreferredencoding = _bootlocale.getpreferredencoding
+            old_getpreferredencoding = locale.getpreferredencoding
             # Indirectly via io.TextIOWrapper, Popen() defaults to
             # locale.getpreferredencoding(False) and earlier in Python 3.2 to
             # locale.getpreferredencoding().
@@ -885,7 +884,7 @@ class ProcessTestCase(BaseTestCase):
                     encoding)
             args = [sys.executable, '-c', code]
             try:
-                _bootlocale.getpreferredencoding = getpreferredencoding
+                locale.getpreferredencoding = getpreferredencoding
                 # We set stdin to be non-None because, as of this writing,
                 # a different code path is used when the number of pipes is
                 # zero or one.
@@ -894,7 +893,7 @@ class ProcessTestCase(BaseTestCase):
                                          stdout=subprocess.PIPE)
                 stdout, stderr = popen.communicate(input='')
             finally:
-                _bootlocale.getpreferredencoding = old_getpreferredencoding
+                locale.getpreferredencoding = old_getpreferredencoding
             self.assertEqual(stdout, '1\n2\n3\n4')
 
     def test_no_leaking(self):
diff --git a/Modules/_io/_iomodule.c b/Modules/_io/_iomodule.c
--- a/Modules/_io/_iomodule.c
+++ b/Modules/_io/_iomodule.c
@@ -564,7 +564,7 @@ PyObject *
         }
         Py_CLEAR(state->locale_module);
     }
-    mod = PyImport_ImportModule("_bootlocale");
+    mod = PyImport_ImportModule("locale");
     if (mod == NULL)
         return NULL;
     state->locale_module = PyWeakref_NewRef(mod, NULL);