diff --git a/.github/workflows/infra.yaml b/.github/workflows/infra.yaml
index fbec85c..fa937da 100644
--- a/.github/workflows/infra.yaml
+++ b/.github/workflows/infra.yaml
@@ -21,9 +21,14 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v3
 
-      - name: Fetch target
+      - name: Fetch PR base
+        if: github.event.pull_request
         run: |
-          git fetch --no-tags --progress --no-recurse-submodules --depth=1 origin ${{ github.event.pull_request.base.ref }}
+          git fetch --no-tags --progress --no-recurse-submodules --depth=1 origin ${{ github.event.pull_request.base.sha }}
+      
+      - name: Test
+        if: github.event.forkee
+        run: echo dot!
 
       - run: |
           echo !${{ github.event.pull_request.base.repo }} !${{ github.event.pull_request.base.sha }}
@@ -46,7 +51,7 @@ jobs:
         id: changed-playbooks
         uses: tj-actions/changed-files@v38
         with:
-          since_last_remote_commit: "true"
+          base_sha: ${{ github.event.pull_request.base.sha }}
           files: infra/**-playbook.yaml
 
       - name: Check modified playbooks