From 76bb881ed3f2ed8029c1e1d16c4959a1b09f31b5 Mon Sep 17 00:00:00 2001
From: Illviljan <14371165+Illviljan@users.noreply.github.com>
Date: Wed, 20 Sep 2023 21:12:18 +0200
Subject: [PATCH] Update groupby.py

---
 xarray/core/groupby.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xarray/core/groupby.py b/xarray/core/groupby.py
index 1b906a52685..e9ddf044568 100644
--- a/xarray/core/groupby.py
+++ b/xarray/core/groupby.py
@@ -699,7 +699,7 @@ class GroupBy(Generic[T_Xarray]):
 
     _groups: dict[GroupKey, GroupIndex] | None
     _dims: tuple[Hashable, ...] | Frozen[Hashable, int] | None
-    _sizes: Frozen[Hashable, int] | None
+    _sizes: Mapping[Hashable, int] | None
 
     def __init__(
         self,