diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c6c4f774..86a10141 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-22.04
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11
       
       - uses: r-lib/actions/setup-r@v2
         with:
@@ -43,7 +43,7 @@ jobs:
         R: [ '4.3.1' ]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11
       
       - uses: r-lib/actions/setup-r@v2
         with: