diff --git a/beetsplug/convert.py b/beetsplug/convert.py
index e08e473f0..8858d710c 100644
--- a/beetsplug/convert.py
+++ b/beetsplug/convert.py
@@ -169,7 +169,12 @@ class ConvertPlugin(BeetsPlugin):
         Raises `subprocess.CalledProcessError` if the command exited with a
         non-zero status code.
         """
-        quiet = self.config['quiet'].get()
+        # The paths and arguments must be bytes.
+        assert isinstance(command, bytes)
+        assert isinstance(source, bytes)
+        assert isinstance(dest, bytes)
+
+        quiet = self.config['quiet'].get(bool)
 
         if not quiet and not pretend:
             self._log.info(u'Encoding {0}', util.displayable_path(source))
@@ -178,8 +183,8 @@ class ConvertPlugin(BeetsPlugin):
         args = shlex.split(command)
         for i, arg in enumerate(args):
             args[i] = Template(arg).safe_substitute({
-                'source': source.decode('utf8'),
-                'dest': dest.decode('utf8'),
+                b'source': source,
+                b'dest': dest,
             })
 
         if pretend:
@@ -391,6 +396,7 @@ class ConvertPlugin(BeetsPlugin):
             command, ext = get_format()
             tmpdir = self.config['tmpdir'].get()
             fd, dest = tempfile.mkstemp('.' + ext, dir=tmpdir)
+            dest = util.bytestring_path(dest)
             os.close(fd)
             _temp_files.append(dest)  # Delete the transcode later.
             try:
diff --git a/test/test_convert.py b/test/test_convert.py
index 3fec8879e..034d8a465 100644
--- a/test/test_convert.py
+++ b/test/test_convert.py
@@ -23,6 +23,7 @@ from test import helper
 from test.helper import control_stdin
 
 from beets.mediafile import MediaFile
+from beets import util
 
 
 class TestHelper(helper.TestHelper):
@@ -105,7 +106,9 @@ class ConvertCliTest(unittest.TestCase, TestHelper):
         self.item = self.album.items()[0]
         self.load_plugins('convert')
 
-        self.convert_dest = os.path.join(self.temp_dir, 'convert_dest')
+        self.convert_dest = util.bytestring_path(
+            os.path.join(self.temp_dir, 'convert_dest')
+        )
         self.config['convert'] = {
             'dest': self.convert_dest,
             'paths': {'default': 'converted'},