diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 796aadf9e4061..32c1ef1ff50f3 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -1205,7 +1205,7 @@ def _maybe_disallow_fill(self, allow_fill: bool, fill_value, indices) -> bool:
         """
 
     @Appender(_index_shared_docs["repeat"] % _index_doc_kwargs)
-    def repeat(self, repeats, axis=None):
+    def repeat(self, repeats, axis: None = None):
         repeats = ensure_platform_int(repeats)
         nv.validate_repeat((), {"axis": axis})
         res_values = self._values.repeat(repeats)