diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5b9a319..7c475b8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,27 @@ See [Conventional Commits](Https://conventionalcommits.org) for commit guideline
 
 <!-- changelog -->
 
+## [v0.9.0](https://github.com/ash-project/reactor/compare/v0.8.5...v0.9.0) (2024-07-18)
+
+
+
+
+### Features:
+
+* map: Add the ability to map over elements of a collection inside a reactor. (#123)
+
+* map: Add the ability to map over elements of a collection inside a reactor.
+
+### Bug Fixes:
+
+* automatically pass extra arguments from the map step to nested steps.
+
+* spurious test failures seemingly caused by `Mimic`.
+
+### Improvements:
+
+* throw a more helpful error when a step returns an invalid result.
+
 ## [v0.8.5](https://github.com/ash-project/reactor/compare/v0.8.4...v0.8.5) (2024-07-10)
 
 
diff --git a/README.md b/README.md
index 8ff5d66..a2e42ec 100644
--- a/README.md
+++ b/README.md
@@ -37,7 +37,7 @@ The package can be installed by adding `reactor` to your list of dependencies in
 ```elixir
 def deps do
   [
-    {:reactor, "~> 0.8.5"}
+    {:reactor, "~> 0.9.0"}
   ]
 end
 ```
diff --git a/mix.exs b/mix.exs
index 42993de..4d8619f 100644
--- a/mix.exs
+++ b/mix.exs
@@ -1,7 +1,7 @@
 defmodule Reactor.MixProject do
   use Mix.Project
 
-  @version "0.8.5"
+  @version "0.9.0"
   @description "An asynchronous, graph-based execution engine"
 
   def project do