diff --git a/py-polars/polars/series/datetime.py b/py-polars/polars/series/datetime.py
index 1ea8af605485..57a2359ff3d7 100644
--- a/py-polars/polars/series/datetime.py
+++ b/py-polars/polars/series/datetime.py
@@ -44,7 +44,7 @@ def add_business_days(
         week_mask: Iterable[bool] = (True, True, True, True, True, False, False),
         holidays: Iterable[dt.date] = (),
         roll: Roll = "raise",
-    ) -> Expr:
+    ) -> Series:
         """
         Offset by `n` business days.