diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6a3f016..ea004eb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php-version: ['8.0', '8.1', '8.2', '8.3', '8.4']
+        php-version: ['8.0', '8.1', '8.2', '8.3', '8.4', '8.5']
         include:
           - php-version: '8.0'
             composer-flags: '--prefer-stable --prefer-lowest'
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 817ecdf..5fd3fd4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,10 @@
 
 # Version 1.x
 
+# 1.2.1
+
+* Test with PHP 8.3 - 8.5.
+
 # 1.2.0
 
 * DateTimeOptions now features a list of deserialization formats instead of a single string one. Passing a string instead of an array to its `__construct`or is deprecated, and will be forbidden in the next version