diff --git a/pandas/core/strings/base.py b/pandas/core/strings/base.py
index 84580ba9c5972..87aa7c26f1304 100644
--- a/pandas/core/strings/base.py
+++ b/pandas/core/strings/base.py
@@ -163,7 +163,7 @@ def _str_wrap(self, width: int, **kwargs):
 
     @abc.abstractmethod
     def _str_get_dummies(
-        self, sep: str = "|", dummy_na: bool = False, dtype: NpDtype = None
+        self, sep: str = "|", dummy_na: bool = False, dtype: NpDtype | None = None
     ):
         pass