diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 30e5779..884ecc1 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
@@ -26,7 +26,7 @@ jobs:
         python: ['3.10', '3.11', '3.12', '3.13', '3.14']
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python }}
         uses: actions/setup-python@v5
         with:
@@ -41,7 +41,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Set up Python
@@ -68,7 +68,7 @@ jobs:
       contents: write
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Set up Python