diff --git a/.github/workflows/test_and_publish.yml b/.github/workflows/test_and_publish.yml
index c164607c..86215d05 100644
--- a/.github/workflows/test_and_publish.yml
+++ b/.github/workflows/test_and_publish.yml
@@ -25,7 +25,7 @@ jobs:
       with:
         path: |
           vendor
-        key: vendor-${{ matrix.php }}-${{ hashFiles('composer.json') }}
+        key: vendor-${{ matrix.php }}-${{ hashFiles('composer.lock') }}
 
     - name: Set up PHP
       uses: shivammathur/setup-php@master