diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0518bd7..e9a7402 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+## 0.4.0
+
+Date: 2024-09-04
+
 - 💄 — Improve email and gotify notifications
 - ✨ — Add command to test gotify configuration
 - ✨ — Add nagios command to use as a Nagios probe
diff --git a/Makefile b/Makefile
index 33d445a..53d3315 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ ORANGE=\033[0;33m
 BLUE=\033[0;34m
 NC=\033[0m # No Color
 
-.PHONY: test lint djlint pylint ruff
+.PHONY: test lint djlint pylint ruff mypy
 
 venv: ## Create the venv
 	python3 -m venv venv
diff --git a/argos/__init__.py b/argos/__init__.py
index a9febb4..6cc293e 100644
--- a/argos/__init__.py
+++ b/argos/__init__.py
@@ -1 +1 @@
-VERSION = "0.3.1"
+VERSION = "0.4.0"
diff --git a/docs/developer/release.md b/docs/developer/release.md
index b30e2b3..8b8e325 100644
--- a/docs/developer/release.md
+++ b/docs/developer/release.md
@@ -23,6 +23,9 @@ git checkout main
 # Ensure the tests run correctly
 make test
 
+# Check static typing
+make mypy
+
 # Bump the version, according to semantic versionning
 hatch version minor # or `hatch version major`, or `hatch version fix`