diff --git a/.github/workflows/pullrequest.yml b/.github/workflows/pullrequest.yml
index 038bbc8..9124348 100644
--- a/.github/workflows/pullrequest.yml
+++ b/.github/workflows/pullrequest.yml
@@ -40,7 +40,7 @@ jobs:
 
       - name: Cache Composer packages
         id: root-composer-cache
-        uses: actions/cache@v5
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
           path: vendor
           key: ${{ runner.os }}-${{ matrix.php-version }}-php-${{ hashFiles('composer.json') }}
@@ -80,7 +80,7 @@ jobs:
 
       - name: Cache Composer packages
         id: behat-composer-cache
-        uses: actions/cache@v5
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
           path: integration/vendor
           key: ${{ runner.os }}-${{ matrix.php-version }}-php-${{ hashFiles('integration/composer.json') }}