diff --git a/tests/test_scrobble.py b/tests/test_scrobble.py
index ab84dbd..cfaf89b 100644
--- a/tests/test_scrobble.py
+++ b/tests/test_scrobble.py
@@ -1,4 +1,6 @@
 # -*- coding: utf-8 -*-
+from unittest.mock import patch
+
 from trakt.movies import Movie
 from trakt.sync import Scrobbler
 
@@ -22,3 +24,28 @@ def test_scrobbler_context_manager():
     with Scrobbler(guardians, 0.0, '1.0.0', '2015-02-01') as scrob:
         for i in range(10):
             scrob.update(i*10)
+
+
+def test_scrobbler_payload_excludes_app_metadata():
+    """scrobble payload must not include undocumented app_version/date fields"""
+    import trakt.core
+    guardians = Movie('Guardians of the Galaxy', year=2014)
+    scrobbler = Scrobbler(guardians, 42.0, '1.0.0', '2015-02-01')
+
+    with patch.object(trakt.core.api(), 'post', return_value=None) as mock_post:
+        scrobbler.start()
+
+    print("call_args:", mock_post.call_args)
+    print("args:", getattr(mock_post.call_args, "args", None))
+    print("tuple:", tuple(mock_post.call_args))
+
+    args, kwargs = mock_post.call_args
+    assert not kwargs
+    assert len(args) >= 2
+    payload = args[-1]
+
+    assert isinstance(payload, dict)
+    assert payload['progress'] == 42.0
+    assert 'app_version' not in payload
+    assert 'app_date' not in payload
+    assert 'date' not in payload
diff --git a/trakt/sync.py b/trakt/sync.py
index 30e9f9d..27382bd 100644
--- a/trakt/sync.py
+++ b/trakt/sync.py
@@ -607,8 +607,7 @@ def _post(self, uri):
 
         :param uri: The uri to post to
         """
-        payload = dict(progress=self.progress, app_version=self.version,
-                       date=self.date)
+        payload = dict(progress=self.progress)
         payload.update(self.media.to_json_singular())
         response = yield uri, payload
         yield response