diff --git a/.github/.codecov.yml b/.github/.codecov.yml
new file mode 100644
index 0000000..d08101f
--- /dev/null
+++ b/.github/.codecov.yml
@@ -0,0 +1,5 @@
+coverage:
+  status:
+    project:
+      default:
+        informational: true
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d3f4f97..e1dec9e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,4 +22,8 @@ jobs:
           npm run compile
       - name: Tests
         run: |
-          npm test
+          npm run coverage
+      - name: Publish to Codecov
+        uses: codecov/codecov-action@v2
+        with:
+          files: coverage/lcov.info
diff --git a/.gitignore b/.gitignore
index e578349..da4d3fb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,7 @@ node_modules
 lib/
 .eslintcache
 docs
+
+# coverage
+.nyc_output
+coverage
diff --git a/package.json b/package.json
index f526f77..faff92c 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,8 @@
   "main": "lib/bigdecimal.js",
   "module": "lib/bigdecimal.mjs",
   "scripts": {
-    "test": "mocha -t 100000 test/**/**/*.js",
+    "test": "mocha --require ts-node/register --require source-map-support/register -t 100000 test/**/**/*.js",
+    "coverage": "nyc --reporter=lcov npm run test",
     "compile": " npm run compile:cjs && npm run compile:esm && npm run prepareESM",
     "compile:esm": "tsc --module es2020 --outDir lib/esm",
     "compile:cjs": "tsc --module commonjs --outDir lib",
@@ -65,8 +66,23 @@
     "chai": "~4.3",
     "eslint": "~7.28.0",
     "mocha": "~9.0.0",
+    "nyc": "^15.1.0",
     "rimraf": "~3.0.2",
+    "source-map-support": "^0.5.19",
+    "ts-node": "^10.2.1",
     "typedoc": "~0.20.36",
     "typescript": "~4.2.4"
+  },
+  "nyc": {
+    "extension": [
+      ".ts"
+    ],
+    "exclude": [
+      "**/*.d.ts"
+    ],
+    "reporter": [
+      "html"
+    ],
+    "all": true
   }
 }
diff --git a/tsconfig.json b/tsconfig.json
index f977246..97f578e 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,7 +4,7 @@
     "stripInternal": true,
     "declaration": true,
     // "outDir": "lib",
-    "sourceMap": false,
+    "sourceMap": true,
     /* Basic Options */
     // "incremental": true,                         /* Enable incremental compilation */
     "target": "es2020",                                /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */