diff --git a/.github/workflows/validate-lockfile.yml b/.github/workflows/validate-lockfile.yml
index b9661a75b..3ac5b5314 100644
--- a/.github/workflows/validate-lockfile.yml
+++ b/.github/workflows/validate-lockfile.yml
@@ -31,11 +31,11 @@ jobs:
             exit 1
           fi
 
-      - name: Ensure pnpm-lock.yaml changes only with package.json
+      - name: Ensure pnpm-lock.yaml changes only when package.json changes
         run: |
-          git fetch origin ${{ github.event.pull_request.base.ref }}
-          git diff --name-only origin/${{ github.event.pull_request.base.ref }}...HEAD > changed_files.txt
-          if grep -q '^pnpm-lock.yaml$' changed_files.txt && ! grep -q 'package.json' changed_files.txt; then
+          git diff --name-only ${{ github.event.pull_request.base.sha }} ${{ github.sha }} > changed_files.txt
+          if grep -q '^pnpm-lock.yaml$' changed_files.txt && \
+             ! grep -q 'package.json' changed_files.txt; then
             echo "❌ pnpm-lock.yaml was changed without any package.json"
             exit 1
           fi