diff --git a/.github/workflows/black.yml b/.github/workflows/black.yml
index 0fd4991..b6db4ea 100644
--- a/.github/workflows/black.yml
+++ b/.github/workflows/black.yml
@@ -14,7 +14,7 @@ jobs:
         python-version: ["3.11"]
         os: [ubuntu-latest]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Black Code Formatter
         uses: lgeiger/black-action@v1.0.1
         with:
diff --git a/.github/workflows/linters.yml b/.github/workflows/linters.yml
index 248bccc..5cf82bd 100644
--- a/.github/workflows/linters.yml
+++ b/.github/workflows/linters.yml
@@ -16,7 +16,7 @@ jobs:
         os: [ubuntu-latest]
         linter-env: ["linting", "type_check"] # linting runs pylint; type_check runs mypy; see tox.ini
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with:
diff --git a/.github/workflows/packaging_test.yml b/.github/workflows/packaging_test.yml
index 9e51df6..770ce5b 100644
--- a/.github/workflows/packaging_test.yml
+++ b/.github/workflows/packaging_test.yml
@@ -14,7 +14,7 @@ jobs:
         python-version: [3.7, 3.8, 3.9, "3.10", "3.11"]
         os: [ubuntu-latest]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with:
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 82a7f0d..c15e84f 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -22,7 +22,7 @@ jobs:
         python-version: [3.11]
         os: [ubuntu-latest]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with:
@@ -39,7 +39,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: tests # under no circumstances we want to publish a release that didn't pass the tests
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
diff --git a/.github/workflows/unittests.yml b/.github/workflows/unittests.yml
index bf78e5b..e97b5d9 100644
--- a/.github/workflows/unittests.yml
+++ b/.github/workflows/unittests.yml
@@ -9,7 +9,7 @@ jobs:
         python-version: [ "3.7", "3.8", "3.9", "3.10", "3.11" ]
         os: [ ubuntu-latest ]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with: