diff --git a/comfy_api_nodes/nodes_bytedance.py b/comfy_api_nodes/nodes_bytedance.py
index df1601faa..1b4abafe6 100644
--- a/comfy_api_nodes/nodes_bytedance.py
+++ b/comfy_api_nodes/nodes_bytedance.py
@@ -317,7 +317,7 @@ async def _seedance_virtual_library_upload_video_asset(
 ) -> str:
     buf = BytesIO()
     video.save_to(buf, format=Types.VideoContainer.MP4, codec=Types.VideoCodec.H264)
-    video_hash = hashlib.sha256(buf.getvalue()).hexdigest()
+    video_hash = hashlib.sha256(buf.getbuffer()).hexdigest()
     public_url = await upload_video_to_comfyapi(cls, video, wait_label=wait_label)
     create_resp = await sync_op(
         cls,