diff --git a/.github/workflows/delete_merged_branch.yml b/.github/workflows/delete_merged_branch.yml
index c041b0efd..6d0a07614 100644
--- a/.github/workflows/delete_merged_branch.yml
+++ b/.github/workflows/delete_merged_branch.yml
@@ -10,7 +10,7 @@ jobs:
     if: github.event.pull_request.merged == true
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3
 
       - name: Delete branch
         run: |