diff --git a/beets/test/helper.py b/beets/test/helper.py
index c0d785d6e..85ea6bcf7 100644
--- a/beets/test/helper.py
+++ b/beets/test/helper.py
@@ -117,20 +117,9 @@ def capture_stdout():
         print(capture.getvalue())
 
 
-def _convert_args(args):
-    """Convert args to bytestrings for Python 2 and convert them to strings
-    on Python 3.
-    """
-    for i, elem in enumerate(args):
-        if isinstance(elem, bytes):
-            args[i] = elem.decode(util.arg_encoding())
-
-    return args
-
-
 def has_program(cmd, args=["--version"]):
     """Returns `True` if `cmd` can be executed."""
-    full_cmd = _convert_args([cmd] + args)
+    full_cmd = [cmd] + args
     try:
         with open(os.devnull, "wb") as devnull:
             subprocess.check_call(
@@ -385,7 +374,7 @@ class TestHelper(_common.Assertions, ConfigMixin):
         if hasattr(self, "lib"):
             lib = self.lib
         lib = kwargs.get("lib", lib)
-        beets.ui._raw_main(_convert_args(list(args)), lib)
+        beets.ui._raw_main(list(args), lib)
 
     def run_with_output(self, *args):
         with capture_stdout() as out:
diff --git a/beets/ui/commands.py b/beets/ui/commands.py
index 99aa04f0a..1822c3e7c 100755
--- a/beets/ui/commands.py
+++ b/beets/ui/commands.py
@@ -1359,13 +1359,8 @@ def import_func(lib, opts, args):
         # what we need. On Python 3, we need to undo the "helpful"
         # conversion to Unicode strings to get the real bytestring
         # filename.
-        paths = [
-            p.encode(util.arg_encoding(), "surrogateescape") for p in paths
-        ]
-        paths_from_logfiles = [
-            p.encode(util.arg_encoding(), "surrogateescape")
-            for p in paths_from_logfiles
-        ]
+        paths = [os.fsencode(p) for p in paths]
+        paths_from_logfiles = [os.fsencode(p) for p in paths_from_logfiles]
 
         # Check the user-specified directories.
         for path in paths:
diff --git a/beets/util/__init__.py b/beets/util/__init__.py
index fea864ce8..68dbaee65 100644
--- a/beets/util/__init__.py
+++ b/beets/util/__init__.py
@@ -369,13 +369,6 @@ def components(path: AnyStr) -> list[AnyStr]:
     return comps
 
 
-def arg_encoding() -> str:
-    """Get the encoding for command-line arguments (and other OS
-    locale-sensitive strings).
-    """
-    return sys.getfilesystemencoding()
-
-
 def bytestring_path(path: PathLike) -> bytes:
     """Given a path, which is either a bytes or a unicode, returns a str
     path (ensuring that we never deal with Unicode pathnames). Path should be
@@ -832,19 +825,6 @@ def plurality(objs: Sequence[T]) -> tuple[T, int]:
     return c.most_common(1)[0]
 
 
-def convert_command_args(args: list[BytesOrStr]) -> list[str]:
-    """Convert command arguments, which may either be `bytes` or `str`
-    objects, to uniformly surrogate-escaped strings."""
-    assert isinstance(args, list)
-
-    def convert(arg) -> str:
-        if isinstance(arg, bytes):
-            return os.fsdecode(arg)
-        return arg
-
-    return [convert(a) for a in args]
-
-
 # stdout and stderr as bytes
 class CommandOutput(NamedTuple):
     stdout: bytes
@@ -869,7 +849,7 @@ def command_output(cmd: list[BytesOrStr], shell: bool = False) -> CommandOutput:
     This replaces `subprocess.check_output` which can have problems if lots of
     output is sent to stderr.
     """
-    converted_cmd = convert_command_args(cmd)
+    converted_cmd = [os.fsdecode(a) for a in cmd]
 
     devnull = subprocess.DEVNULL
 
diff --git a/beetsplug/convert.py b/beetsplug/convert.py
index 0c50fc73f..a8c32e955 100644
--- a/beetsplug/convert.py
+++ b/beetsplug/convert.py
@@ -28,7 +28,7 @@ from confuse import ConfigTypeError, Optional
 from beets import art, config, plugins, ui, util
 from beets.library import Item, parse_query_string
 from beets.plugins import BeetsPlugin
-from beets.util import arg_encoding, par_map
+from beets.util import par_map
 from beets.util.artresizer import ArtResizer
 from beets.util.m3u import M3UFile
 
@@ -284,7 +284,7 @@ class ConvertPlugin(BeetsPlugin):
         if not quiet and not pretend:
             self._log.info("Encoding {0}", util.displayable_path(source))
 
-        command = command.decode(arg_encoding(), "surrogateescape")
+        command = os.fsdecode(command)
         source = os.fsdecode(source)
         dest = os.fsdecode(dest)
 
@@ -298,7 +298,7 @@ class ConvertPlugin(BeetsPlugin):
                     "dest": dest,
                 }
             )
-            encode_cmd.append(args[i].encode(util.arg_encoding()))
+            encode_cmd.append(os.fsdecode(args[i]))
 
         if pretend:
             self._log.info("{0}", " ".join(ui.decargs(args)))
diff --git a/beetsplug/hook.py b/beetsplug/hook.py
index c7f8091cb..5ce5ef828 100644
--- a/beetsplug/hook.py
+++ b/beetsplug/hook.py
@@ -17,9 +17,9 @@
 import shlex
 import string
 import subprocess
+import sys
 
 from beets.plugins import BeetsPlugin
-from beets.util import arg_encoding
 
 
 class CodingFormatter(string.Formatter):
@@ -73,7 +73,7 @@ class HookPlugin(BeetsPlugin):
 
             # For backwards compatibility, use a string formatter that decodes
             # bytes (in particular, paths) to unicode strings.
-            formatter = CodingFormatter(arg_encoding())
+            formatter = CodingFormatter(sys.getfilesystemencoding())
             command_pieces = [
                 formatter.format(piece, event=event, **kwargs)
                 for piece in shlex.split(command)
diff --git a/test/plugins/test_convert.py b/test/plugins/test_convert.py
index 2fd1d177b..a2b4eaf67 100644
--- a/test/plugins/test_convert.py
+++ b/test/plugins/test_convert.py
@@ -143,18 +143,13 @@ class ConvertCommand:
     in tests.
     """
 
-    def run_convert_path(self, path, *args):
+    def run_convert_path(self, item, *args):
         """Run the `convert` command on a given path."""
-        # The path is currently a filesystem bytestring. Convert it to
-        # an argument bytestring.
-        path = os.fsencode(os.fsdecode(path))
-
-        args = args + (b"path:" + path,)
-        return self.run_command("convert", *args)
+        return self.run_command("convert", *args, f"path:{item.filepath}")
 
     def run_convert(self, *args):
         """Run the `convert` command on `self.item`."""
-        return self.run_convert_path(self.item.path, *args)
+        return self.run_convert_path(self.item, *args)
 
 
 @_common.slow_test()
@@ -320,7 +315,7 @@ class NeverConvertLossyFilesTest(ConvertTestCase, ConvertCommand):
     def test_transcode_from_lossless(self):
         [item] = self.add_item_fixtures(ext="flac")
         with control_stdin("y"):
-            self.run_convert_path(item.path)
+            self.run_convert_path(item)
         converted = os.path.join(self.convert_dest, b"converted.mp3")
         self.assertFileTag(converted, "mp3")
 
@@ -328,14 +323,14 @@ class NeverConvertLossyFilesTest(ConvertTestCase, ConvertCommand):
         self.config["convert"]["never_convert_lossy_files"] = False
         [item] = self.add_item_fixtures(ext="ogg")
         with control_stdin("y"):
-            self.run_convert_path(item.path)
+            self.run_convert_path(item)
         converted = os.path.join(self.convert_dest, b"converted.mp3")
         self.assertFileTag(converted, "mp3")
 
     def test_transcode_from_lossy_prevented(self):
         [item] = self.add_item_fixtures(ext="ogg")
         with control_stdin("y"):
-            self.run_convert_path(item.path)
+            self.run_convert_path(item)
         converted = os.path.join(self.convert_dest, b"converted.ogg")
         self.assertNoFileTag(converted, "mp3")
 
diff --git a/test/plugins/test_thumbnails.py b/test/plugins/test_thumbnails.py
index 00cd545d4..bd3e22714 100644
--- a/test/plugins/test_thumbnails.py
+++ b/test/plugins/test_thumbnails.py
@@ -100,12 +100,10 @@ class ThumbnailsTest(BeetsTestCase):
 
     @patch("beetsplug.thumbnails.ThumbnailsPlugin._check_local_ok", Mock())
     @patch("beetsplug.thumbnails.ArtResizer")
-    @patch("beetsplug.thumbnails.util")
+    @patch("beets.util.syspath", Mock(side_effect=lambda x: x))
     @patch("beetsplug.thumbnails.os")
     @patch("beetsplug.thumbnails.shutil")
-    def test_make_cover_thumbnail(
-        self, mock_shutils, mock_os, mock_util, mock_artresizer
-    ):
+    def test_make_cover_thumbnail(self, mock_shutils, mock_os, mock_artresizer):
         thumbnail_dir = os.path.normpath(b"/thumbnail/dir")
         md5_file = os.path.join(thumbnail_dir, b"md5")
         path_to_art = os.path.normpath(b"/path/to/art")
@@ -116,7 +114,6 @@ class ThumbnailsTest(BeetsTestCase):
         plugin.add_tags = Mock()
 
         album = Mock(artpath=path_to_art)
-        mock_util.syspath.side_effect = lambda x: x
         plugin.thumbnail_file_name = Mock(return_value=b"md5")
         mock_os.path.exists.return_value = False
 
diff --git a/test/rsrc/convert_stub.py b/test/rsrc/convert_stub.py
index cba693c4e..aec4ba572 100755
--- a/test/rsrc/convert_stub.py
+++ b/test/rsrc/convert_stub.py
@@ -4,18 +4,9 @@
 a specified text tag.
 """
 
-import locale
 import sys
 
 
-# From `beets.util`.
-def arg_encoding():
-    try:
-        return locale.getdefaultlocale()[1] or "utf-8"
-    except ValueError:
-        return "utf-8"
-
-
 def convert(in_file, out_file, tag):
     """Copy `in_file` to `out_file` and append the string `tag`."""
     if not isinstance(tag, bytes):
diff --git a/test/test_ui.py b/test/test_ui.py
index 6c23b321f..e9588dbc6 100644
--- a/test/test_ui.py
+++ b/test/test_ui.py
@@ -865,6 +865,9 @@ class ConfigTest(TestPluginTestCase):
 
         # Custom BEETSDIR
         self.beetsdir = os.path.join(self.temp_dir, b"beetsdir")
+        self.cli_config_path = os.path.join(
+            os.fsdecode(self.temp_dir), "config.yaml"
+        )
         os.makedirs(syspath(self.beetsdir))
         self.env_patcher = patch(
             "os.environ",
@@ -952,20 +955,18 @@ class ConfigTest(TestPluginTestCase):
         assert repls == [("[xy]", "z"), ("foo", "bar")]
 
     def test_cli_config_option(self):
-        config_path = os.path.join(self.temp_dir, b"config.yaml")
-        with open(config_path, "w") as file:
+        with open(self.cli_config_path, "w") as file:
             file.write("anoption: value")
-        self.run_command("--config", config_path, "test", lib=None)
+        self.run_command("--config", self.cli_config_path, "test", lib=None)
         assert config["anoption"].get() == "value"
 
     def test_cli_config_file_overwrites_user_defaults(self):
         with open(self.user_config_path, "w") as file:
             file.write("anoption: value")
 
-        cli_config_path = os.path.join(self.temp_dir, b"config.yaml")
-        with open(cli_config_path, "w") as file:
+        with open(self.cli_config_path, "w") as file:
             file.write("anoption: cli overwrite")
-        self.run_command("--config", cli_config_path, "test", lib=None)
+        self.run_command("--config", self.cli_config_path, "test", lib=None)
         assert config["anoption"].get() == "cli overwrite"
 
     def test_cli_config_file_overwrites_beetsdir_defaults(self):
@@ -974,10 +975,9 @@ class ConfigTest(TestPluginTestCase):
         with open(env_config_path, "w") as file:
             file.write("anoption: value")
 
-        cli_config_path = os.path.join(self.temp_dir, b"config.yaml")
-        with open(cli_config_path, "w") as file:
+        with open(self.cli_config_path, "w") as file:
             file.write("anoption: cli overwrite")
-        self.run_command("--config", cli_config_path, "test", lib=None)
+        self.run_command("--config", self.cli_config_path, "test", lib=None)
         assert config["anoption"].get() == "cli overwrite"
 
     #    @unittest.skip('Difficult to implement with optparse')
@@ -998,29 +998,27 @@ class ConfigTest(TestPluginTestCase):
     #
     #    @unittest.skip('Difficult to implement with optparse')
     #    def test_multiple_cli_config_overwrite(self):
-    #        cli_config_path = os.path.join(self.temp_dir, b'config.yaml')
     #        cli_overwrite_config_path = os.path.join(self.temp_dir,
     #                                                 b'overwrite_config.yaml')
     #
-    #        with open(cli_config_path, 'w') as file:
+    #        with open(self.cli_config_path, 'w') as file:
     #            file.write('anoption: value')
     #
     #        with open(cli_overwrite_config_path, 'w') as file:
     #            file.write('anoption: overwrite')
     #
-    #        self.run_command('--config', cli_config_path,
+    #        self.run_command('--config', self.cli_config_path,
     #                      '--config', cli_overwrite_config_path, 'test')
     #        assert config['anoption'].get() == 'cli overwrite'
 
     # FIXME: fails on windows
     @unittest.skipIf(sys.platform == "win32", "win32")
     def test_cli_config_paths_resolve_relative_to_user_dir(self):
-        cli_config_path = os.path.join(self.temp_dir, b"config.yaml")
-        with open(cli_config_path, "w") as file:
+        with open(self.cli_config_path, "w") as file:
             file.write("library: beets.db\n")
             file.write("statefile: state")
 
-        self.run_command("--config", cli_config_path, "test", lib=None)
+        self.run_command("--config", self.cli_config_path, "test", lib=None)
         self.assert_equal_path(
             util.bytestring_path(config["library"].as_filename()),
             os.path.join(self.user_config_dir, b"beets.db"),
@@ -1033,12 +1031,11 @@ class ConfigTest(TestPluginTestCase):
     def test_cli_config_paths_resolve_relative_to_beetsdir(self):
         os.environ["BEETSDIR"] = os.fsdecode(self.beetsdir)
 
-        cli_config_path = os.path.join(self.temp_dir, b"config.yaml")
-        with open(cli_config_path, "w") as file:
+        with open(self.cli_config_path, "w") as file:
             file.write("library: beets.db\n")
             file.write("statefile: state")
 
-        self.run_command("--config", cli_config_path, "test", lib=None)
+        self.run_command("--config", self.cli_config_path, "test", lib=None)
         self.assert_equal_path(
             util.bytestring_path(config["library"].as_filename()),
             os.path.join(self.beetsdir, b"beets.db"),
@@ -1057,12 +1054,11 @@ class ConfigTest(TestPluginTestCase):
         )
 
     def test_cli_config_file_loads_plugin_commands(self):
-        cli_config_path = os.path.join(self.temp_dir, b"config.yaml")
-        with open(cli_config_path, "w") as file:
+        with open(self.cli_config_path, "w") as file:
             file.write("pluginpath: %s\n" % _common.PLUGINPATH)
             file.write("plugins: test")
 
-        self.run_command("--config", cli_config_path, "plugin", lib=None)
+        self.run_command("--config", self.cli_config_path, "plugin", lib=None)
         assert plugins.find_plugins()[0].is_test_plugin
         self.unload_plugins()
 
@@ -1483,9 +1479,7 @@ class CommonOptionsParserCliTest(BeetsTestCase):
         assert output == "the album artist\n"
 
     def test_format_option_unicode(self):
-        output = self.run_with_output(
-            b"ls", b"-f", "caf\xe9".encode(util.arg_encoding())
-        )
+        output = self.run_with_output("ls", "-f", "caf\xe9")
         assert output == "caf\xe9\n"
 
     def test_root_format_option(self):
diff --git a/test/test_util.py b/test/test_util.py
index 85534949f..f5b4fd102 100644
--- a/test/test_util.py
+++ b/test/test_util.py
@@ -97,13 +97,6 @@ class UtilTest(unittest.TestCase):
             p = util.sanitize_path("foo//bar", [(re.compile(r"^$"), "_")])
         assert p == "foo/_/bar"
 
-    @unittest.skipIf(sys.platform == "win32", "win32")
-    def test_convert_command_args_keeps_undecodeable_bytes(self):
-        arg = b"\x82"  # non-ascii bytes
-        cmd_args = util.convert_command_args([arg])
-
-        assert cmd_args[0] == arg.decode(util.arg_encoding(), "surrogateescape")
-
     @patch("beets.util.subprocess.Popen")
     def test_command_output(self, mock_popen):
         def popen_fail(*args, **kwargs):