diff --git a/narwhals/_pandas_like/group_by.py b/narwhals/_pandas_like/group_by.py
index ee18dc7f13..f65bb7674d 100644
--- a/narwhals/_pandas_like/group_by.py
+++ b/narwhals/_pandas_like/group_by.py
@@ -47,7 +47,7 @@ def __init__(self, df: PandasLikeDataFrame, keys: list[str]) -> None:
                 list(self._keys),
                 sort=False,
                 as_index=True,
-                dropna=False,
+                dropna=True,
                 observed=True,
             )