diff --git a/.github/workflows/draft-pdf.yml b/.github/workflows/draft-pdf.yml
index bbf79f08..941885b5 100644
--- a/.github/workflows/draft-pdf.yml
+++ b/.github/workflows/draft-pdf.yml
@@ -10,7 +10,7 @@ jobs:
     name: Paper Draft
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Build draft PDF
         uses: openjournals/openjournals-draft-action@master
         with:
diff --git a/.github/workflows/unit_tests.yml b/.github/workflows/unit_tests.yml
index 6d17c41b..ee06509c 100644
--- a/.github/workflows/unit_tests.yml
+++ b/.github/workflows/unit_tests.yml
@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup Python 3.9
         uses: actions/setup-python@v4
         with:
@@ -71,7 +71,7 @@ jobs:
         shell: bash
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with:
@@ -121,7 +121,7 @@ jobs:
         shell: bash
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: main # clone repository in a sub-directory
       - name: Setup Python ${{ matrix.python-version }}
@@ -179,7 +179,7 @@ jobs:
     if: startsWith(github.ref, 'refs/tags/')
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with: