diff --git a/.github/workflows/check.yaml b/.github/workflows/check.yaml
index 3091d11..08d17a4 100644
--- a/.github/workflows/check.yaml
+++ b/.github/workflows/check.yaml
@@ -27,16 +27,19 @@ jobs:
         with:
           fetch-depth: 0  # Complete git history is required to generate the version from git tags.
 
-      - name: Setup Python 3.10
+      - name: Set up Python 3.10
         uses: actions/setup-python@v5
         with:
-          python-version: '3.10'
+          python-version: "3.10"
 
       - name: Install dependencies
         run: |
           sudo apt update
           sudo apt install -y yamllint
-          pipx install tox
+          python -m pip install --upgrade pip
+          # pin tox to the current major version to avoid
+          # workflows breaking all at once when a new major version is released.
+          python -m pip install 'tox<5'
 
       - name: Lint yaml files
         run: yamllint .yamllint snap/snapcraft.yaml
@@ -68,19 +71,23 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0  # Complete git history is required to generate the version from git tags.
 
       - name: Download the built snap
         uses: actions/download-artifact@v4
         with:
           name: SNAP_FILE
 
-      - name: Setup Python 3.10
+      - name: Set up Python 3.10
         uses: actions/setup-python@v5
         with:
-          python-version: '3.10'
+          python-version: "3.10"
 
       - name: Install dependencies
-        run: pipx install tox
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install 'tox<5'
 
-      - name: Run tests
+      - name: Run unit tests
         run: tox -e func