diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e4979a0..5be9517 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup OCaml
         uses: ocaml/setup-ocaml@v3
diff --git a/.github/workflows/deploy-doc.yml b/.github/workflows/deploy-doc.yml
index aadad5b..c6969c6 100644
--- a/.github/workflows/deploy-doc.yml
+++ b/.github/workflows/deploy-doc.yml
@@ -16,7 +16,7 @@ jobs:
         shell: bash
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
diff --git a/.github/workflows/test-deploy-doc.yml b/.github/workflows/test-deploy-doc.yml
index 8e171cd..0d6d3ff 100644
--- a/.github/workflows/test-deploy-doc.yml
+++ b/.github/workflows/test-deploy-doc.yml
@@ -16,7 +16,7 @@ jobs:
         shell: bash
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0