diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 8a9510a..7f67f94 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     container: python:3.10
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
       - name: Get the version from the tag.
@@ -48,7 +48,7 @@ jobs:
       - inspect
       - github_release
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install twine.
         run: pip install twine
       - name: Set the version number.
diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 5d5b00f..d95c123 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     container: python:3.10
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install package.
         run: pip install -e .
       - name: Install test dependencies.
@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     container: python:3.10
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install package.
         run: pip install .
       - name: Build the test site.
@@ -28,7 +28,7 @@ jobs:
     runs-on: ubuntu-latest
     container: python:3.10
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install the linter (flake8).
         run: pip install flake8
       - name: Run the linter.
@@ -37,7 +37,7 @@ jobs:
     runs-on: ubuntu-latest
     container: python:3.10
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Install package.
         run: pip install .
       - name: Install mypy.
diff --git a/setup.py b/setup.py
index 44e7860..9585baa 100644
--- a/setup.py
+++ b/setup.py
@@ -49,7 +49,7 @@
         'itsdangerous==2.1.2',
         'jinja2==3.1.2',
         'markdown==3.4.1',
-        'markupsafe==2.1.1',
+        'markupsafe==3.0.0',
         'pygments==2.13.0',
         'pymdown-extensions==9.7',
         'pyscss==1.4.0',