diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 148fe57..e71c2cb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,14 +19,17 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: '7.1.27'
+      - name: Validate composer.json and composer.lock
+        run: |
+          sudo composer self-update
       - name: Cache Composer packages
         id: composer-cache
         uses: actions/cache@v3
         with:
           path: vendor
-          key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
+          key: composer-v1-{{ checksum "composer.lock" }}
           restore-keys: |
-            ${{ runner.os }}-php-
+            composer-v1-
       - run: composer install --prefer-dist --no-progress
       - name: siftPhpTest
         run: composer exec phpunit -v