diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index c3bbe956..d3aa7837 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -3,7 +3,8 @@
 
 - Modify coroutine sink to make it discard log messages when ``loop=None`` and no event loop is running (due to internally using ``asyncio.get_running_loop()`` in place of ``asyncio.get_event_loop()``).
 - Remove the possibility to add a coroutine sink with ``enqueue=True`` if ``loop=None`` and no event loop is running.
-- Prevent non-ascii characters to be escaped while logging JSON message with ``serialize=True`` (`#574 <https://github.com/Delgan/loguru/pull/575>`_, thanks `@ponponon <https://github.com/ponponon>`_).
+- Change default encoding of file sink to be ``utf8`` instead of ``locale.getpreferredencoding()`` (`#339 <https://github.com/Delgan/loguru/issues/339>`_).
+- Prevent non-ascii characters to be escaped while logging JSON message with ``serialize=True`` (`#575 <https://github.com/Delgan/loguru/pull/575>`_, thanks `@ponponon <https://github.com/ponponon>`_).
 - Fix ``flake8`` errors and improve code readability (`#353 <https://github.com/Delgan/loguru/issues/353>`_, thanks `@AndrewYakimets <https://github.com/AndrewYakimets>`_).
 
 
diff --git a/loguru/_file_sink.py b/loguru/_file_sink.py
index 691e3a74..5f48f512 100644
--- a/loguru/_file_sink.py
+++ b/loguru/_file_sink.py
@@ -1,7 +1,6 @@
 import datetime as datetime_
 import decimal
 import glob
-import locale
 import numbers
 import os
 import shutil
@@ -147,10 +146,10 @@ def __init__(
         delay=False,
         mode="a",
         buffering=1,
-        encoding=None,
+        encoding="utf8",
         **kwargs
     ):
-        self.encoding = locale.getpreferredencoding(False) if encoding is None else encoding
+        self.encoding = encoding
 
         self._kwargs = {**kwargs, "mode": mode, "buffering": buffering, "encoding": self.encoding}
         self._path = str(path)
diff --git a/loguru/_logger.py b/loguru/_logger.py
index 88474614..e2c66fdf 100644
--- a/loguru/_logger.py
+++ b/loguru/_logger.py
@@ -38,7 +38,6 @@
 .. |contextvars| replace:: :mod:`contextvars`
 .. |Thread.run| replace:: :meth:`Thread.run()<threading.Thread.run()>`
 .. |Exception| replace:: :class:`Exception`
-.. |locale.getpreferredencoding| replace:: :func:`locale.getpreferredencoding()`
 .. |AbstractEventLoop| replace:: :class:`AbstractEventLoop<asyncio.AbstractEventLoop>`
 .. |asyncio.get_running_loop| replace:: :func:`asyncio.get_running_loop()`
 .. |asyncio.run| replace:: :func:`asyncio.run()`
@@ -304,8 +303,7 @@ def add(
             The buffering policy as for built-in |open| function. It defaults to ``1`` (line
             buffered file).
         encoding : |str|, optional
-            The file encoding as for built-in |open| function. If ``None``, it defaults to
-            |locale.getpreferredencoding|.
+            The file encoding as for built-in |open| function. It defaults to ``"utf8"``.
         **kwargs
             Others parameters are passed to the built-in |open| function.
 
diff --git a/tests/test_add_sinks.py b/tests/test_add_sinks.py
index d1b4fab3..d53fd2cd 100644
--- a/tests/test_add_sinks.py
+++ b/tests/test_add_sinks.py
@@ -159,6 +159,14 @@ def test_file_sink_utf8_encoding(tmpdir):
     assert file.read_text("utf8") == "天\n"
 
 
+def test_file_sink_default_encoding(tmpdir):
+    file = tmpdir.join("test.log")
+    logger.add(str(file), format="{message}", errors="strict", catch=False)
+    logger.info("天")
+    logger.remove()
+    assert file.read_text("utf8") == "天\n"
+
+
 def test_disabled_logger_in_sink(sink_with_logger):
     sink = sink_with_logger(logger)
     logger.disable("tests.conftest")