diff --git a/pymongo/_version.py b/pymongo/_version.py
index 75ec22cc5a..5ff72d6cc8 100644
--- a/pymongo/_version.py
+++ b/pymongo/_version.py
@@ -18,7 +18,7 @@
 import re
 from typing import List, Tuple, Union
 
-__version__ = "4.9"
+__version__ = "4.10.0.dev0"
 
 
 def get_version_tuple(version: str) -> Tuple[Union[int, str], ...]: