diff --git a/test/test_filesystem.py b/test/test_filesystem.py
new file mode 100644
index 000000000..b004e3abd
--- /dev/null
+++ b/test/test_filesystem.py
@@ -0,0 +1,89 @@
+# -*- coding: utf-8 -*-
+import os.path
+import picard.formats
+import unittest
+import shutil
+from contextlib import suppress
+
+from PyQt5 import QtCore
+from picard import config
+from tempfile import mkdtemp
+from test.test_formats import FakeTagger
+
+
+settings = {
+    'enabled_plugins': '',
+    'move_files': True,
+    'move_additional_files': True,
+    'move_additional_files_pattern': 'cover.jpg',
+}
+
+
+class TestFileSystem(unittest.TestCase):
+
+    def setUp(self):
+        self.src_directory = mkdtemp()
+        self.tgt_directory = mkdtemp()
+        QtCore.QObject.tagger = FakeTagger()
+        config.setting = settings.copy()
+
+    def tearDown(self):
+        shutil.rmtree(self.src_directory)
+        shutil.rmtree(self.tgt_directory)
+
+    def _set_up_src_file(self, filename, src_rel_path):
+        """Copy filename to the src directory under src_rel_path."""
+        path = os.path.join(self.src_directory, src_rel_path)
+        shutil.copy(filename, path)
+        return path
+
+    def _set_up_tgt_filename(self, tgt_rel_path):
+        """Return the absolute path to tgt_rel_path in the tgt directory."""
+        return os.path.join(self.tgt_directory, tgt_rel_path)
+
+    def _prepare_files(self, src_rel_path='', tgt_rel_path=''):
+        """Prepare src files and tgt filenames for a test."""
+        with suppress(FileExistsError):
+            os.mkdir(os.path.join(self.src_directory, src_rel_path))
+
+        # Prepare the source directory structure under self.src_directory
+        # .../<src_rel_path>/test.mp3
+        # .../<src_rel_path>/cover.jpg
+
+        old_filename = self._set_up_src_file(os.path.join('test', 'data', 'test.mp3'),
+                                             os.path.join(src_rel_path, 'test.mp3'))
+        old_additional_filename = self._set_up_src_file(os.path.join('test', 'data', 'mb.jpg'),
+                                                        os.path.join(src_rel_path, 'cover.jpg'))
+
+        with suppress(FileExistsError):
+            os.mkdir(os.path.join(self.tgt_directory, tgt_rel_path))
+
+        # Prepare the target filenames under self.tgt_directory
+        # .../<tgt_rel_path>/test.mp3
+        # .../<tgt_rel_path>/cover.jpg
+
+        new_filename = self._set_up_tgt_filename(os.path.join(tgt_rel_path, 'test.mp3'))
+
+        new_additional_filename = self._set_up_tgt_filename(os.path.join(tgt_rel_path, 'cover.jpg'))
+
+        return (old_filename, old_additional_filename, new_filename, new_additional_filename)
+
+    def test_move_additional_files_source_unicode(self):
+        files = self._prepare_files(src_rel_path='música')
+        (old_filename, old_additional_filename, new_filename, new_additional_filename) = files
+
+        f = picard.formats.open_(old_filename)
+        f._move_additional_files(old_filename, new_filename)
+
+        self.assertTrue(os.path.isfile(new_additional_filename))
+        self.assertFalse(os.path.isfile(old_additional_filename))
+
+    def test_move_additional_files_target_unicode(self):
+        files = self._prepare_files(tgt_rel_path='música')
+        (old_filename, old_additional_filename, new_filename, new_additional_filename) = files
+
+        f = picard.formats.open_(old_filename)
+        f._move_additional_files(old_filename, new_filename)
+
+        self.assertTrue(os.path.isfile(new_additional_filename))
+        self.assertFalse(os.path.isfile(old_additional_filename))
diff --git a/test/test_formats.py b/test/test_formats.py
index e4f28a827..3ddb89599 100644
--- a/test/test_formats.py
+++ b/test/test_formats.py
@@ -39,6 +39,7 @@ class FakeTagger(QtCore.QObject):
         QtCore.QObject.log = log
         self.tagger_stats_changed.connect(self.emit)
         self.exit_cleanup = []
+        self.files = {}
 
     def register_cleanup(self, func):
         self.exit_cleanup.append(func)