diff --git a/sanguo_data/index_downloader.py b/sanguo_data/index_downloader.py
index d4b24b2..a033162 100644
--- a/sanguo_data/index_downloader.py
+++ b/sanguo_data/index_downloader.py
@@ -41,7 +41,7 @@ def download_index(symbol: str, start_year: int, end_year: int, out_dir: str) ->
                 start_date=start_date,
                 end_date=end_date,
                 frequency="d",
-                adjustfield="3"  # 不复权
+                adjustflag="3"  # 不复权
             )
 
             if rs.error_code not in ("0", "success"):