diff --git a/xarray/core/groupby.py b/xarray/core/groupby.py
index edfb6c85905..0bc3d01c13d 100644
--- a/xarray/core/groupby.py
+++ b/xarray/core/groupby.py
@@ -36,8 +36,8 @@
 from xarray.core.pycompat import integer_types
 from xarray.core.types import Dims, QuantileMethods, T_DataArray, T_Xarray
 from xarray.core.utils import (
-    either_dict_or_kwargs,
     Frozen,
+    either_dict_or_kwargs,
     hashable,
     is_scalar,
     maybe_wrap_array,