diff --git a/src/PIL/_version.py b/src/PIL/_version.py
index dbed769ed..12d7412ea 100644
--- a/src/PIL/_version.py
+++ b/src/PIL/_version.py
@@ -1,4 +1,4 @@
 # Master version for Pillow
 from __future__ import annotations
 
-__version__ = "10.3.0"
+__version__ = "10.4.0.dev0"