diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
new file mode 100644
index 0000000..fecff90
--- /dev/null
+++ b/.github/workflows/release.yml
@@ -0,0 +1,42 @@
+  on: push
+  name: Release workflow
+  jobs:
+    build-phar:
+      runs-on: ubuntu-latest
+      steps:
+        - uses: actions/checkout@master
+
+        - name: Setup PHP
+          uses: shivammathur/setup-php@master
+          with:
+            php-version: 7.4
+            ini-values: memory_limit=2G, display_errors=On, error_reporting=-1, phar.readonly=0
+            tools: pecl, phive
+
+        - name: Get composer cache directory
+          id: composer-cache
+          run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+
+        - name: Cache composer dependencies
+          uses: actions/cache@v2
+          with:
+            path: ${{ steps.composer-cache.outputs.dir }}
+            key: composer-${{ hashFiles('**/composer.lock') }}
+            restore-keys: composer-
+
+        - name: Install Composer dependencies
+          run: |
+            composer install --no-progress --prefer-dist --optimize-autoloader
+
+        - name: Install phive tools
+          run: phive install --trust-gpg-keys 2A8299CE842DD38C
+
+        - name: Create build dir
+          run: make phar
+
+        - name: Upload PHAR file
+          uses: actions/upload-artifact@v2.2.0
+          with:
+            name: prophecy-phpunit.phar
+            path: build/prophecy-phpunit.phar
+
diff --git a/.gitignore b/.gitignore
index a79486f..2763146 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 vendor
+build
 composer.lock
 phpunit.xml
diff --git a/.phive/phars.xml b/.phive/phars.xml
new file mode 100644
index 0000000..a5cb741
--- /dev/null
+++ b/.phive/phars.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phive xmlns="https://phar.io/phive">
+  <phar name="phpab" version="^1.26.0" installed="1.26.0" location="./tools/phpab" copy="true"/>
+</phive>
diff --git a/composer.json b/composer.json
index 2c48d3b..a4c7e5c 100644
--- a/composer.json
+++ b/composer.json
@@ -15,8 +15,11 @@
     "prefer-stable": true,
     "require": {
         "php": "^7.3 || ^8",
-        "phpspec/prophecy": "^1.3",
-        "phpunit/phpunit":"^9.1"
+        "phpspec/prophecy": "^1.3"
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^9.5",
+        "phar-io/manifest": "^2.0"
     },
     "autoload": {
         "psr-4": {
diff --git a/makefile b/makefile
new file mode 100644
index 0000000..c5318a4
--- /dev/null
+++ b/makefile
@@ -0,0 +1,11 @@
+phar:
+	mkdir build;
+	cp -r src build/src;
+	cp -r vendor build;
+	rm -r build/vendor/phpspec;
+	cp manifest.xml build/manifest.xml;
+	cp LICENSE build/LICENSE
+	php -dphar.readonly=0 ./tools/phpab --phar -o ./build/prophecy-phpunit.phar --all --hash SHA-1 ./build
+
+clean:
+	rm -r build
diff --git a/manifest.xml b/manifest.xml
new file mode 100644
index 0000000..2c5352d
--- /dev/null
+++ b/manifest.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<phar xmlns="https://phar.io/xml/manifest/1.0">
+    <contains name="prophecy/prophecy-phpunit" version="1.0" type="extension">
+        <extension for="phpunit/phpunit" compatible="^9.1"/>
+    </contains>
+
+    <copyright>
+        <author name="Christophe Coevoet" email="stof@notk.org"/>
+        <license type="MIT" url="https://github.com/phpspec/prophecy-phpunit/blob/master/LICENSE"/>
+    </copyright>
+
+    <requires>
+        <php version="^7.3 || ^8.0"/>
+    </requires>
+</phar>