diff --git a/python/cudf/cudf/core/groupby/groupby.py b/python/cudf/cudf/core/groupby/groupby.py
index cffe2d7d6a5..6a298df32d6 100644
--- a/python/cudf/cudf/core/groupby/groupby.py
+++ b/python/cudf/cudf/core/groupby/groupby.py
@@ -720,7 +720,7 @@ def shift(self, periods=1, freq=None, axis=0, fill_value=None):
             The scalar value to use for newly introduced missing values. Can be
             specified with `None`, a single value or multiple values:
 
-            - `None` (default): do not perform fill
+            - `None` (default): sets all indeterminable values to null.
             - Single value: fill all shifted columns with this value. Should
               match the data type of all columns.
             - List of values: fill shifted columns with corresponding value in