diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 0c4071e00ec7c..a2adcb9add9cc 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -4,6 +4,14 @@
 
 ## Rails 7.1.0.beta1 (September 13, 2023) ##
 
+*   Add `bigdecimal` as Active Support dependency that is a bundled gem candidate for Ruby 3.4.
+
+    `bigdecimal` 3.1.4 or higher version will be installed.
+    Ruby 2.7 and 3.0 users who want `bigdecimal` version 2.0.0 or 3.0.0 behavior as a default gem,
+    pin the `bigdecimal` version in your application Gemfile.
+
+    *Koichi ITO*
+
 *   Add `drb`, `mutex_m` and `base64` that are bundled gem candidates for Ruby 3.4
 
     *Yasuo Honda*