diff --git a/CHANGELOG.md b/CHANGELOG.md
index b028ea8..600bdd0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,12 @@
 
 All notable changes to this project will be documented in this file.
 
+0.9.1 (unreleased)
+------------------
+
+- Nothing changed yet.
+
+
 0.9.0 (2023-02-10)
 ------------------
 
diff --git a/setup.cfg b/setup.cfg
index cd409e4..a379672 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = mypy-zope
-version = 0.9.0
+version = 0.9.1.dev0
 author = Andrey Lebedev
 author_email = andrey.lebedev@gmail.com
 url = https://github.com/Shoobx/mypy-zope