diff --git a/doc/whats-new.rst b/doc/whats-new.rst
index 2dc271061e4..828e8da4b44 100644
--- a/doc/whats-new.rst
+++ b/doc/whats-new.rst
@@ -33,6 +33,10 @@ Deprecations
 
 Bug fixes
 ~~~~~~~~~
+- Fix a minor incompatibility between partial datetime string indexing with a
+  :py:class:`CFTimeIndex` and upcoming pandas version 1.3.0 (:issue:`5356`,
+  :pull:`5359`).
+  By `Spencer Clark <https://github.com/spencerkclark>`_.
 
 
 Documentation
diff --git a/xarray/coding/cftimeindex.py b/xarray/coding/cftimeindex.py
index f0de55656fa..783fe8d04d9 100644
--- a/xarray/coding/cftimeindex.py
+++ b/xarray/coding/cftimeindex.py
@@ -465,9 +465,14 @@ def get_loc(self, key, method=None, tolerance=None):
         else:
             return pd.Index.get_loc(self, key, method=method, tolerance=tolerance)
 
-    def _maybe_cast_slice_bound(self, label, side, kind):
+    def _maybe_cast_slice_bound(self, label, side, kind=None):
         """Adapted from
-        pandas.tseries.index.DatetimeIndex._maybe_cast_slice_bound"""
+        pandas.tseries.index.DatetimeIndex._maybe_cast_slice_bound
+
+        Note that we have never used the kind argument in CFTimeIndex and it is
+        deprecated as of pandas version 1.3.0.  It exists only for compatibility
+        reasons.  We can remove it when our minimum version of pandas is 1.3.0.
+        """
         if not isinstance(label, str):
             return label