diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e2acf77..44402bd 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -33,8 +33,16 @@ jobs:
       - name: Lint with ruff
         run: uv run ruff check src/ tests/
 
-      - name: Run tests
-        run: uv run pytest tests/ -v
+      - name: Run tests with coverage
+        run: uv run pytest --cov --cov-report=xml
+
+      - name: Upload coverage to Codecov
+        if: matrix.os == 'ubuntu-latest'
+        uses: codecov/codecov-action@v5
+        with:
+          files: coverage.xml
+          fail_ci_if_error: false
+          token: ${{ secrets.CODECOV_TOKEN }}
 
   smoke-macos:
     runs-on: macos-latest
diff --git a/README.md b/README.md
index 0833fe8..6dcedc7 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,7 @@
 [![Python versions](https://img.shields.io/pypi/pyversions/yt-dont-recommend)](https://pypi.org/project/yt-dont-recommend/)
 [![License](https://img.shields.io/pypi/l/yt-dont-recommend)](https://github.com/cmeans/yt-dont-recommend/blob/main/LICENSE)
 [![CI](https://img.shields.io/github/actions/workflow/status/cmeans/yt-dont-recommend/ci.yml?label=CI)](https://github.com/cmeans/yt-dont-recommend/actions/workflows/ci.yml)
+[![Coverage](https://codecov.io/gh/cmeans/yt-dont-recommend/graph/badge.svg)](https://codecov.io/gh/cmeans/yt-dont-recommend)
 [![Downloads](https://img.shields.io/pypi/dm/yt-dont-recommend)](https://pypi.org/project/yt-dont-recommend/)
 
 > **Early development / alpha:** This tool is functional and used daily by its author, but it is under active development with frequent releases. Breaking changes between versions are possible. **Auto-upgrade is not recommended** until the tool stabilises — enable it only if you are comfortable testing new features as they land and are willing to use `--revert` when something goes wrong.
diff --git a/pyproject.toml b/pyproject.toml
index 7fd86bc..22d7010 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,6 +21,7 @@ Changelog = "https://github.com/cmeans/yt-dont-recommend/blob/main/CHANGELOG.md"
 [project.optional-dependencies]
 dev = [
     "pytest",
+    "pytest-cov>=7.0",
     "pyyaml",
     "ruff",
 ]
@@ -61,3 +62,10 @@ ignore = [
 
 [tool.ruff.lint.isort]
 known-first-party = ["yt_dont_recommend"]
+
+[tool.coverage.run]
+source = ["yt_dont_recommend"]
+
+[tool.coverage.report]
+show_missing = true
+skip_empty = true