diff --git a/tests/unit/test_audio_only_clips_in_filter_complex.py b/tests/unit/test_audio_only_clips_in_filter_complex.py
index d3e93fa7a..41f7f257e 100644
--- a/tests/unit/test_audio_only_clips_in_filter_complex.py
+++ b/tests/unit/test_audio_only_clips_in_filter_complex.py
@@ -7,10 +7,11 @@ Bug: voice.mp3（纯音频文件）被错误地加入视频 filter_complex，
 因为音频 clips 由 mix_audio() 独立处理。
 """
 
-import pytest
 from pathlib import Path
 from unittest.mock import MagicMock
 
+import pytest
+
 
 def _make_render_service(tmp_path):
     """创建一个最小化的 UnifiedRenderService 实例."""