diff --git a/.github/workflows/mainline-compile.yml b/.github/workflows/mainline-compile.yml
index e9162ec..5d6c866 100644
--- a/.github/workflows/mainline-compile.yml
+++ b/.github/workflows/mainline-compile.yml
@@ -23,7 +23,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
           fetch-depth: 0
diff --git a/.github/workflows/mainline-format.yml b/.github/workflows/mainline-format.yml
index fdc6d75..f869eab 100644
--- a/.github/workflows/mainline-format.yml
+++ b/.github/workflows/mainline-format.yml
@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           submodules: true
 
diff --git a/.github/workflows/mainline-lint.yml b/.github/workflows/mainline-lint.yml
index 903e0a0..9dc0057 100644
--- a/.github/workflows/mainline-lint.yml
+++ b/.github/workflows/mainline-lint.yml
@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           submodules: true
diff --git a/.github/workflows/mainline-prepare.yml b/.github/workflows/mainline-prepare.yml
index 7b6d63e..0bb0e35 100644
--- a/.github/workflows/mainline-prepare.yml
+++ b/.github/workflows/mainline-prepare.yml
@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Log in to GHCR
         uses: docker/login-action@v3
diff --git a/.github/workflows/version-increment.yml b/.github/workflows/version-increment.yml
index e09cba6..98355d3 100644
--- a/.github/workflows/version-increment.yml
+++ b/.github/workflows/version-increment.yml
@@ -30,7 +30,7 @@ jobs:
       contains(github.event.head_commit.message, '[ci-major-increase]')
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0