diff --git a/changelog.md b/changelog.md
index 17a3567..8c3f36b 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,15 @@
 # changelog
 
+## v0.5.0 (unreleased)
+
+### changes
+
+- TBD
+
+### fixes
+
+- TBD
+
 ## v0.4.0 (2026-01-02)
 
 ### changes
diff --git a/pyproject.toml b/pyproject.toml
index aac960f..db4784e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [project]
 name = "takopi"
 authors = [{name = "banteg"}]
-version = "0.4.0"
+version = "0.5.0.dev0"
 description = "Run OpenAI Codex CLI with Telegram as the human-in-the-loop interface."
 readme = "readme.md"
 license = { file = "LICENSE" }
diff --git a/src/takopi/__init__.py b/src/takopi/__init__.py
index 6a9beea..8a640e5 100644
--- a/src/takopi/__init__.py
+++ b/src/takopi/__init__.py
@@ -1 +1 @@
-__version__ = "0.4.0"
+__version__ = "0.5.0.dev0"