diff --git a/mopidy/frontends/mpd/translator.py b/mopidy/frontends/mpd/translator.py
index ccd83fde..f66c64a7 100644
--- a/mopidy/frontends/mpd/translator.py
+++ b/mopidy/frontends/mpd/translator.py
@@ -87,6 +87,8 @@ def uri_to_mpd_relative_path(uri):
     :type uri: string
     :rtype: string
     """
+    if uri is None:
+        return ''
     path = path_to_uri(settings.LOCAL_MUSIC_FOLDER)
     return re.sub('^' + re.escape(path), '', uri)
 
diff --git a/tests/frontends/mpd/serializer_test.py b/tests/frontends/mpd/serializer_test.py
index cd9320b6..960e5ebd 100644
--- a/tests/frontends/mpd/serializer_test.py
+++ b/tests/frontends/mpd/serializer_test.py
@@ -67,6 +67,11 @@ class UriToMpdRelativePathTest(unittest.TestCase):
     def tearDown(self):
         settings.runtime.clear()
 
+    def test_none_file_returns_empty_string(self):
+        uri = 'file:///dir/subdir/music/album/song.mp3'
+        result = translator.uri_to_mpd_relative_path(None)
+        self.assertEqual('', result)
+
     def test_file_gets_stripped(self):
         uri = 'file:///dir/subdir/music/album/song.mp3'
         result = translator.uri_to_mpd_relative_path(uri)