diff --git a/.github/workflows/tox.yml b/.github/workflows/tox.yml
index c2c6efb..662de17 100644
--- a/.github/workflows/tox.yml
+++ b/.github/workflows/tox.yml
@@ -14,10 +14,9 @@ jobs:
   build:
     runs-on: ubuntu-latest
     strategy:
-      max-parallel: 5
+      max-parallel: 4
       matrix:
-        python-version: [3.5, 3.6, 3.7, 3.8, 3.9]
-        tox-testenv: ["test", "test-rapidjson"]
+        python-version: [3.5, 3.6, 3.7, 3.8]
 
     steps:
     - uses: actions/checkout@v1
@@ -28,11 +27,15 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install tox
+        pip install tox tox-gh-actions
     - name: Test with tox
       run: |
         pyenv="py$(echo "${{ matrix.python-version }}" | tr -d '.')"
         tox -e ${pyenv},${{ matrix.tox-testenv }},flake8,lint
+    - name: Upload to coverage
+      uses: codecov/codecov-action@v1.2.1
+      with:
+        flags: ${{ matrix.python-version }}
     - name: Publish package to PyPI
       uses: pypa/gh-action-pypi-publish@master
       if: >-
diff --git a/setup.cfg b/setup.cfg
index cacbbb4..fd60efa 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -2,7 +2,7 @@
 addopts = -v --junit-xml=test-report.xml
           --doctest-modules
           --cov=riotctrl --cov-branch
-          --cov-report=term --cov-report=xml --cov-report=html
+          --cov-report=term --cov-report=term-missing --cov-report=xml
 testpaths = riotctrl
 markers =
     rapidjson