diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 469adac6..6e338415 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,8 +18,14 @@ jobs:
 
       - uses: actions/setup-node@v2
         with:
-          node-version: '16'
+          node-version: "16"
 
       - run: |
           npm clean-install
           npm run test
+
+      - name: Upload coverage results to Coveralls
+        uses: coverallsapp/github-action@master
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          path-to-lcov: ./test/coverage/lcov.info
diff --git a/jest.config.js b/jest.config.js
index 87c30aa4..5d800eeb 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -1,4 +1,14 @@
 module.exports = {
   preset: 'ts-jest',
   testEnvironment: 'node',
+  collectCoverage: true,
+  coverageDirectory: './test/coverage',
+  coverageReporters: ['json', 'html', 'lcov'],
+  collectCoverageFrom: [
+    './src/**/*.{js,ts}',
+    './test/**/*.ts',
+    '!**/node_modules/**',
+    '!**/vendor/**',
+    '!**/vendor/**',
+  ],
 }
diff --git a/package.json b/package.json
index e440b5ab..ab56b8a7 100644
--- a/package.json
+++ b/package.json
@@ -38,7 +38,7 @@
     "docs": "typedoc src/index.ts --out docs/v2",
     "docs:json": "typedoc --json docs/v2/spec.json --excludeExternals src/index.ts",
     "test": "run-s format:check test:types db:clean db:run test:run db:clean && node test/smoke.cjs && node test/smoke.mjs",
-    "test:run": "jest --runInBand",
+    "test:run": "jest --runInBand --coverage",
     "test:update": "run-s db:clean db:run && jest --runInBand --updateSnapshot && run-s db:clean",
     "test:types": "run-s build && tsd --files 'test/**/*.test-d.ts'",
     "db:clean": "cd test/db && docker compose down --volumes",