diff --git a/mopidy/mpd/handler.py b/mopidy/mpd/handler.py
index ef7274f8..65c00ceb 100644
--- a/mopidy/mpd/handler.py
+++ b/mopidy/mpd/handler.py
@@ -66,7 +66,7 @@ class MpdHandler(object):
                 response.append(u'%s: %s' % (key, value))
             else:
                 response.append(line)
-        if add_ok:
+        if add_ok and (not response or not response[-1].startswith(u'ACK')):
             response.append(u'OK')
         return response
 
@@ -109,6 +109,8 @@ class MpdHandler(object):
             response = self.handle_request(command, add_ok=False)
             if response is not None:
                 result.append(response)
+            if response and response[-1].startswith(u'ACK'):
+                return result
             if command_list_ok:
                 response.append(u'list_OK')
         return result