diff --git a/.github/workflows/CI-master_tests.yml b/.github/workflows/CI-master_tests.yml
index 9522f94..1f15118 100644
--- a/.github/workflows/CI-master_tests.yml
+++ b/.github/workflows/CI-master_tests.yml
@@ -119,7 +119,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v1
         with:
           persist-credentials: false
           # Otherwise, you will failed to push refs to dest repo.