diff --git a/nyc.config.js b/nyc.config.js
new file mode 100644
index 000000000..cdc8932ce
--- /dev/null
+++ b/nyc.config.js
@@ -0,0 +1,21 @@
+
+module.exports = {
+    include: [
+        'src/**',
+    ],
+    exclude: [
+        'src/bin/*',
+        'src/lib/BufferedDuplex.ts',
+        'src/connect/wx.ts',
+        'src/connect/ali.ts',
+    ],
+    reporter: [
+        'text',
+        'lcov',
+    ],
+    branches: 80,
+    functions: 89,
+    lines: 86,
+    statements: 86,
+    'check-coverage': true,
+}
\ No newline at end of file
diff --git a/package.json b/package.json
index ac95f4a29..a97bc7016 100644
--- a/package.json
+++ b/package.json
@@ -63,7 +63,7 @@
     "build:browser": "node esbuild.js",
     "build": "npm run build:ts && npm run build:browser",
     "prepare": "npm run build",
-    "unit-test:node": "node_modules/.bin/nyc --reporter=lcov --reporter=text node -r esbuild-register test/runTests.ts",
+    "unit-test:node": "node_modules/.bin/nyc node -r esbuild-register test/runTests.ts",
     "unit-test:browser": "wtr",
     "test:node": "npm run unit-test:node && codecov",
     "test:browser": "npm run build && npm run unit-test:browser",
diff --git a/src/lib/connect/ws.ts b/src/lib/connect/ws.ts
index f44c3ddd8..f98ec481e 100644
--- a/src/lib/connect/ws.ts
+++ b/src/lib/connect/ws.ts
@@ -120,6 +120,7 @@ function createWebSocket(
 	return socket
 }
 
+/* istanbul ignore next */
 function createBrowserWebSocket(client: MqttClient, opts: IClientOptions) {
 	const websocketSubProtocol =
 		opts.protocolId === 'MQIsdp' && opts.protocolVersion === 3
@@ -154,6 +155,7 @@ const streamBuilder: StreamBuilder = (client, opts) => {
 	return webSocketStream
 }
 
+/* istanbul ignore next */
 const browserStreamBuilder: StreamBuilder = (client, opts) => {
 	debug('browserStreamBuilder')
 	let stream: BufferedDuplex | (Transform & { socket?: WebSocket })