diff --git a/src/anthias_server/celery_tasks.py b/src/anthias_server/celery_tasks.py
index 60d4d3111..fdb70cc36 100755
--- a/src/anthias_server/celery_tasks.py
+++ b/src/anthias_server/celery_tasks.py
@@ -760,14 +760,16 @@ def _validate_remote_video_response(resp: Any, uri: str) -> None:
             'live streams are not auto-downloaded'
         )
     # Accept ``video/*`` and ``application/octet-stream`` (some CDNs
-    # serve video files this way). An empty Content-Type also passes
-    # — a few origins omit it. Anything else (HTML error page, JSON
-    # error envelope) gets rejected so we don't store a 200 OK error
-    # page as the asset.
+    # serve video files this way). Reject everything else, including
+    # an empty Content-Type. Well-behaved origins always send one; a
+    # missing header is a stronger signal of a misbehaving origin
+    # than evidence of a real video — and accepting it would let an
+    # HTML error page land on disk as a multi-GB asset, where the
+    # row stays orphaned because the cleanup() sweep won't touch a
+    # file that's still referenced by an (errored) row.
     if (
         base_type.startswith('video/')
         or base_type == 'application/octet-stream'
-        or base_type == ''
     ):
         return
     raise RemoteVideoDownloadError(
diff --git a/tests/test_celery_tasks.py b/tests/test_celery_tasks.py
index 0676b694f..ab87df7db 100644
--- a/tests/test_celery_tasks.py
+++ b/tests/test_celery_tasks.py
@@ -1208,6 +1208,35 @@ def test_download_remote_video_asset_accepts_octet_stream(
     mock_dispatch.assert_called_once_with('rv-1')
 
 
+@pytest.mark.django_db
+def test_download_remote_video_asset_empty_content_type_aborts(
+    remote_video_asset_dir: str,
+) -> None:
+    """A 200 OK with no Content-Type header is a stronger signal of a
+    misbehaving origin than evidence of a real video. Accepting it
+    would let an HTML error page land on disk as a multi-GB asset
+    that the cleanup sweep can't recover (the row still references
+    the file, so it isn't an orphan). Reject and let the operator
+    see the explicit Content-Type-missing failure on the row."""
+    _make_remote_video_asset(remote_video_asset_dir)
+    with (
+        mock.patch(
+            'anthias_server.celery_tasks._session.get',
+            return_value=_fake_response(content_type='', body=b'whatever'),
+        ),
+        mock.patch('anthias_server.processing.dispatch_normalize_video'),
+        mock.patch('anthias_server.app.consumers.notify_asset_update'),
+    ):
+        with pytest.raises(RemoteVideoDownloadError, match='Content-Type'):
+            download_remote_video_asset(
+                'rv-1', 'https://example.com/no-headers.mp4'
+            )
+    # Nothing landed on disk; the staging cleanup wiped the .part too.
+    dest = path.join(remote_video_asset_dir, 'rv-1.mp4')
+    assert not path.exists(dest)
+    assert not path.exists(f'{dest}.part')
+
+
 @pytest.mark.django_db
 def test_download_remote_video_asset_zero_bytes_aborts(
     remote_video_asset_dir: str,