diff --git a/CHANGELOG.md b/CHANGELOG.md
index e1a71fd..b20adb4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Notable Changes in openslide-bin
 
+## Version 4.0.0.6, 2024-09-29
+
+* Switch from zlib to zlib-ng
+* Export type hints from Python package
+* Reduce size of source archive
+* Update various dependencies
+
+
 ## Version 4.0.0.5, 2024-09-10
 
 * Add Linux aarch64 build
diff --git a/common/meson.py b/common/meson.py
index 348c4ef..015d2c3 100644
--- a/common/meson.py
+++ b/common/meson.py
@@ -34,7 +34,7 @@
 # A.B.C = OpenSlide version
 # D = ordinal of the openslide-bin release with this A.B.C, starting from 1
 # Update the version when releasing openslide-bin.
-_PROJECT_VERSION = '4.0.0.5'
+_PROJECT_VERSION = '4.0.0.6'
 
 
 def meson_source_root() -> Path: