diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8cdcec3..cf1ef63 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,7 +23,7 @@ jobs:
       matrix:
         python: ["3.11", "3.12"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set up Python
         uses: actions/setup-python@v5
@@ -52,7 +52,7 @@ jobs:
     name: ruff + mypy
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set up Python
         uses: actions/setup-python@v5
diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index c687073..b2efcad 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -23,7 +23,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: Initialize CodeQL
       uses: github/codeql-action/init@v3
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 6a08a8e..207dd1c 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -43,7 +43,7 @@ jobs:
     name: pytest + lint (release gate)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-python@v5
         with:
@@ -80,7 +80,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: guard
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-python@v5
         with:
@@ -136,7 +136,7 @@ jobs:
     needs: publish
     if: startsWith(github.ref, 'refs/tags/v')
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0