diff --git a/.github/workflows/release-phar.yml b/.github/workflows/release-phar.yml
index b9c45a744..467e575db 100644
--- a/.github/workflows/release-phar.yml
+++ b/.github/workflows/release-phar.yml
@@ -8,16 +8,22 @@ name: Append phpbench.phar to release
 jobs:
   build:
     name: Compile and upload Phar
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
 
+      - name: Set PHP 7.3
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '7.3'
+
       - name: Compile phpbench.phar
         run: |
           composer install
           wget https://github.com/box-project/box/releases/download/3.9.1/box.phar
           php box.phar compile -c box.json.gh-release
+
       - name: Check existence of compiled .phar
         run: test -e phpbench.phar && exit 0 || exit 10