diff --git a/mopidy/mpd/frontend.py b/mopidy/mpd/frontend.py
index 58402959..c45ef4f2 100644
--- a/mopidy/mpd/frontend.py
+++ b/mopidy/mpd/frontend.py
@@ -79,7 +79,10 @@ class MpdFrontend(object):
             matches = re.match(pattern, request)
             if matches is not None:
                 return (_request_handlers[pattern], matches.groupdict())
-        raise MpdUnknownCommand(command=request.split(' ')[0])
+        command = request.split(' ')[0]
+        if command in _commands:
+            raise MpdArgError(u'incorrect arguments', command=command)
+        raise MpdUnknownCommand(command=command)
 
     def handle_response(self, result, add_ok=True):
         response = []
diff --git a/tests/mpd/frontend_test.py b/tests/mpd/frontend_test.py
index 6cb77415..a03d1b17 100644
--- a/tests/mpd/frontend_test.py
+++ b/tests/mpd/frontend_test.py
@@ -993,8 +993,7 @@ class MusicDatabaseHandlerTest(unittest.TestCase):
 
     def test_list_artist_with_artist_should_fail(self):
         result = self.h.handle_request(u'list "artist" "anartist"')
-        self.assertEqual(result[0],
-            u'ACK [2@0] {list} should be "Album" for 3 arguments')
+        self.assertEqual(result[0], u'ACK [2@0] {list} incorrect arguments')
 
     def test_list_album_without_artist(self):
         result = self.h.handle_request(u'list "album"')