diff --git a/controller/api/bilirecorder_blueprint.py b/controller/api/bilirecorder_blueprint.py
index a7af3ea..457f78c 100644
--- a/controller/api/bilirecorder_blueprint.py
+++ b/controller/api/bilirecorder_blueprint.py
@@ -109,7 +109,7 @@ def collect_danmaku_files(workflow: Optional[Workflow]):
         if start_time_ts is None:
             if clip.duration is None or clip.duration == 0:
                 clip.duration = get_video_real_duration(clip.full_path)
-            start_time_ts = datetime.now().timestamp() - clip.duration
+            start_time_ts = datetime.now().timestamp() - float(clip.duration)
         for danmaku_file in glob(os.path.join(XIGUALIVE_RECORDER_DIRECTORY, "*.xml")):
             relpath = os.path.relpath(danmaku_file, XIGUALIVE_RECORDER_DIRECTORY)
             danmaku = DanmakuClip.query.filter(