diff --git a/setup.cfg b/setup.cfg
index d5feb8a..8cf0a43 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = python-socketio
-version = 5.5.2
+version = 5.5.3.dev0
 author = Miguel Grinberg
 author_email = miguel.grinberg@gmail.com
 description = Socket.IO server and client for Python