diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 62d8e646..66c8af09 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -15,10 +15,10 @@ jobs:
       - name: Check out repository code
         uses: actions/checkout@v3
 
-      - name: Setup PHP 7.4
+      - name: Setup PHP 8.1
         uses: shivammathur/setup-php@v2
         with:
-          php-version: 7.4
+          php-version: 8.1
           ini-values: phar.readonly = false
 
       - name: Build PHAR
diff --git a/Makefile b/Makefile
index 2afc7aea..ea8096c8 100644
--- a/Makefile
+++ b/Makefile
@@ -72,11 +72,11 @@ ifeq (, $(wildcard vendor))
 endif
 
 build/box.phar:
-	@cd build && curl -LSs https://box-project.github.io/box2/installer.php | php
+	curl -LSs https://github.com/box-project/box/releases/download/4.3.8/box.phar -o build/box.phar
 
 build/moodle-plugin-ci.phar: build/box.phar
 	$(COMPOSER) install --no-dev --prefer-dist --classmap-authoritative --quiet
-	php -d memory_limit=-1 -d phar.readonly=false build/box.phar build
+	php -d memory_limit=-1 -d phar.readonly=false build/box.phar compile
 	$(COMPOSER) install --prefer-dist --quiet
 
 docs/CLI.md: $(CMDS)
diff --git a/box.json b/box.json
index de6013ac..6d59f39d 100644
--- a/box.json
+++ b/box.json
@@ -1,5 +1,4 @@
 {
-  "chmod": "0755",
   "compression": "GZ",
   "directories": [
     "src",
@@ -39,13 +38,11 @@
       ]
     }
   ],
-  "compactors": "Herrera\\Box\\Compactor\\Php",
+  "compactors": "KevinGH\\Box\\Compactor\\Php",
   "git-version": "package_version",
   "replacements": {
     "is_boxed": "BOXED"
   },
   "intercept": true,
-  "main": "bin/moodle-plugin-ci",
-  "output": "build/moodle-plugin-ci.phar",
-  "stub": true
-}
\ No newline at end of file
+  "output": "build/moodle-plugin-ci.phar"
+}
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 3733334f..49475769 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -9,6 +9,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 The format of this change log follows the advice given at [Keep a CHANGELOG](http://keepachangelog.com).
 
 ## [Unreleased]
+### Fixed
+- Updated the PHAR packaging utility ([box](https://github.com/box-project/box)) to actual one, to avoid various issues happening with PHP 8.1 and up.
+
 ## [4.1.2] - 2023-09-02
 ### Changed
 - Modified `moodle-local_ci` composer dependencies and manage them normally, removing some ancient bits that have [stopped working with Composer 2.6.0 and up](https://github.com/composer/composer/issues/11613).