diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a35c32743..fb8a735fb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -44,3 +44,19 @@ jobs:
         # Fake a TTY
         shell: 'script -q -e -c "bash --noprofile --norc -eo pipefail {0}"'
         run: "python -m tox"
+  coverage:
+    name: "Upload coverage"
+    runs-on: "ubuntu-latest"
+    needs: tests
+    steps:
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          directory: .
+          env_vars: OS,PYTHON
+          fail_ci_if_error: true
+          files: ./coverage.xml
+          flags: unittests
+          name: codecov-umbrella
+          verbose: true
diff --git a/tox.ini b/tox.ini
index 80d30619f..773b1fd88 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,21 +1,17 @@
 [tox]
 envlist = {py38,py310,py311}-tests,py39-tests-{pytz2018.7,pytz_latest}
 skip_missing_interpreters = True
+work_dir = {env:TOX_WORK_DIR:.tox}
 
 [testenv]
 ignore_errors = True
 passenv =
   LANG
   CI
-  TRAVIS
-  TRAVIS_BRANCH
-  TRAVIS_BUILD_ID
-  TRAVIS_COMMIT
-  TRAVIS_JOB_ID
-  TRAVIS_JOB_NUMBER
-  TRAVIS_PULL_REQUEST
-  TRAVIS_REPO_SLUG
+set_env =
+    COVERAGE_FILE = {env:COVERAGE_FILE:{toxworkdir}/.coverage.{envname}}
 deps =
+    coverage
     pytest
     freezegun
     !py36: vdirsyncer
@@ -26,7 +22,11 @@ deps =
     hypothesis
 
 commands =
-    py.test {posargs}
+    coverage run -m pytest {posargs}
+    sh -c "coverage combine -q .tox/.coverage.* && coverage xml || true && coverage report"
+allowlist_externals =
+    coverage
+    sh
 
 [gh-actions]
 python =