diff --git a/.github/workflows/phpcs_on_pull_request.yml b/.github/workflows/phpcs_on_pull_request.yml
index b81c19a..f040bd4 100644
--- a/.github/workflows/phpcs_on_pull_request.yml
+++ b/.github/workflows/phpcs_on_pull_request.yml
@@ -12,14 +12,14 @@ jobs:
     - name: Run PHPCS inspection with PHP 8.1
       uses: rtCamp/action-phpcs-code-review@master
       env:
-        SKIP_FOLDERS: "tests,.github"
+        SKIP_FOLDERS: "tests,.github,vendor"
         GH_BOT_TOKEN: ${{ secrets.RTBOT_TOKEN }}
 
     # Remove this step once WordPress Coding Standards supports PHP 8.0+.
     - name: Run PHPCS inspection with PHP 7.4
       uses: rtCamp/action-phpcs-code-review@master
       env:
-        SKIP_FOLDERS: "tests,.github"
+        SKIP_FOLDERS: "tests,.github,vendor"
         PHPCS_PHP_VERSION: "7.4"
         PHPCS_STANDARD_FILE_NAME: "phpcs.wpcs.xml"
         GH_BOT_TOKEN: ${{ secrets.RTBOT_TOKEN }}