diff --git a/CHANGELOG.md b/CHANGELOG.md
index 82b0e582..f24a0cc0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Bump to minimum PHP 7.2 ([#746](https://github.com/jsonrainbow/json-schema/pull/746))
 - Replace traditional syntax array with short syntax array ([#747](https://github.com/jsonrainbow/json-schema/pull/747))
 - Increase phpstan level to 8 with baseline to swallow existing errors ([#673](https://github.com/jsonrainbow/json-schema/pull/673))
+- Add ext-json to composer.json to ensure JSON extension available  ([#759](https://github.com/jsonrainbow/json-schema/pull/759))
 
 ## [6.0.0] - 2024-07-30
 ### Added
diff --git a/composer.json b/composer.json
index 9a7b1246..516fb8a8 100644
--- a/composer.json
+++ b/composer.json
@@ -28,6 +28,7 @@
     ],
     "require": {
         "php": "^7.2 || ^8.0",
+        "ext-json": "*",
         "marc-mabe/php-enum":"^2.0 || ^3.0 || ^4.0",
         "icecave/parity": "^3.0"
     },