diff --git a/CHANGELOG.md b/CHANGELOG.md
index 26c6297..57db76d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ this file is about the package, whose version moves independently.
 
 ## Unreleased
 
+## 0.9.0
+
 - **Breaking: a trip is a sequence of parts, and records no dates of its own.** §6.8 and the
   new §6.9a of
   [the specification](https://github.com/divejson/divejson/blob/main/spec/divejson.md) replace
diff --git a/divejson/__init__.py b/divejson/__init__.py
index f6207b7..90887c4 100644
--- a/divejson/__init__.py
+++ b/divejson/__init__.py
@@ -20,7 +20,7 @@
 resolves its own schema and needs no checkout of anything.
 """
 
-__version__ = "0.8.0"
+__version__ = "0.9.0"
 
 SPEC_VERSION = "1.0"