diff --git a/.github/workflows/bench.yml b/.github/workflows/bench.yml
index 033bfab6e..f5f790fb2 100644
--- a/.github/workflows/bench.yml
+++ b/.github/workflows/bench.yml
@@ -8,6 +8,11 @@ jobs:
     name: benchmark current
     runs-on: ubuntu-latest
     steps:
+      - run: |
+          echo ${{ gihub.base_ref }} > base_ref
+          if [[ ! -s base_ref ]]; then
+            echo 'no-target' > base_ref
+          fi
       - uses: actions/checkout@v2
         with:
           ref: ${{ github.base_ref }}
@@ -15,7 +20,7 @@ jobs:
         with:
           node-version: 12
       - run: npm i
-      - run: npm run bench | tee ${{ github.base_ref }}.txt
+      - run: npm run bench | tee $(basename $(cat base_ref)).txt
 
   benchmark_branch:
     name: benchmark branch
@@ -26,4 +31,4 @@ jobs:
         with:
           node-version: 12
       - run: npm i
-      - run: npm run bench | tee ${{ github.ref }}.txt
+      - run: npm run bench | tee $(basename ${{ github.ref }}).txt