diff --git a/altair/__init__.py b/altair/__init__.py
index 428ddd01b..f36525661 100644
--- a/altair/__init__.py
+++ b/altair/__init__.py
@@ -1,5 +1,5 @@
 # ruff: noqa
-__version__ = "5.2.0"
+__version__ = "5.3.0dev"
 
 from typing import Any
 
diff --git a/doc/conf.py b/doc/conf.py
index 6aa76c19d..4240cf77e 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -78,7 +78,7 @@
 # built documents.
 #
 # The short X.Y version.
-version = "5.2.0"
+version = "5.3.0dev"
 # The full version, including alpha/beta/rc tags.
 release = f"{version}"
 
diff --git a/doc/releases/changes.rst b/doc/releases/changes.rst
index 7a6bc296a..206e7f8c3 100644
--- a/doc/releases/changes.rst
+++ b/doc/releases/changes.rst
@@ -3,6 +3,16 @@
 Release Notes
 =============
 
+Version 5.3.0 (unreleased month day, year)
+--------------------------
+
+Enhancements
+~~~~~~~~~~~~
+Bug Fixes
+~~~~~~~~~
+Backward-Incompatible Changes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
 Version 5.2.0 (released Nov 28, 2023)
 -------------------------------------------
 - Update Vega-Lite from version 5.15.1 to version 5.16.3;