diff --git a/test/addons/async-hello-world/test-makecallback.js b/test/addons/async-hello-world/test-makecallback.js
index 0edf052e8c34fc..abbc4be9c680c3 100644
--- a/test/addons/async-hello-world/test-makecallback.js
+++ b/test/addons/async-hello-world/test-makecallback.js
@@ -3,7 +3,7 @@ const common = require('../../common');
 const assert = require('assert');
 const { runMakeCallback } = require(`./build/${common.buildType}/binding`);
 
-runMakeCallback(5, common.mustCall(function(err, val) {
+runMakeCallback(5, common.mustCall((err, val) => {
   assert.strictEqual(err, null);
   assert.strictEqual(val, 10);
   process.nextTick(common.mustCall());
diff --git a/test/addons/async-hello-world/test.js b/test/addons/async-hello-world/test.js
index f24071087c0629..72b31f7ab6ec20 100644
--- a/test/addons/async-hello-world/test.js
+++ b/test/addons/async-hello-world/test.js
@@ -3,7 +3,7 @@ const common = require('../../common');
 const assert = require('assert');
 const { runCall } = require(`./build/${common.buildType}/binding`);
 
-runCall(5, common.mustCall(function(err, val) {
+runCall(5, common.mustCall((err, val) => {
   assert.strictEqual(err, null);
   assert.strictEqual(val, 10);
   process.nextTick(common.mustCall());
diff --git a/test/addons/load-long-path/test.js b/test/addons/load-long-path/test.js
index 168dad492b0255..9a9d0763994b08 100644
--- a/test/addons/load-long-path/test.js
+++ b/test/addons/load-long-path/test.js
@@ -48,6 +48,6 @@ fs.writeFileSync(addonDestinationPath, contents);
 
 // Run test
 const child = fork(__filename, ['child'], { stdio: 'inherit' });
-child.on('exit', common.mustCall(function(code) {
+child.on('exit', common.mustCall((code) => {
   assert.strictEqual(code, 0);
 }));
diff --git a/test/addons/make-callback-domain-warning/test.js b/test/addons/make-callback-domain-warning/test.js
index 2ea3c3f3d14b2b..0377415e1269aa 100644
--- a/test/addons/make-callback-domain-warning/test.js
+++ b/test/addons/make-callback-domain-warning/test.js
@@ -10,23 +10,23 @@ function makeCallback(object, cb) {
 }
 
 let latestWarning = null;
-process.on('warning', function(warning) {
+process.on('warning', (warning) => {
   latestWarning = warning;
 });
 
 const d = domain.create();
 
 // When domain is disabled, no warning will be emitted
-makeCallback({ domain: d }, common.mustCall(function() {
+makeCallback({ domain: d }, common.mustCall(() => {
   assert.strictEqual(latestWarning, null);
 
-  d.run(common.mustCall(function() {
+  d.run(common.mustCall(() => {
     // No warning will be emitted when no domain property is applied
-    makeCallback({}, common.mustCall(function() {
+    makeCallback({}, common.mustCall(() => {
       assert.strictEqual(latestWarning, null);
 
       // Warning is emitted when domain property is used and domain is enabled
-      makeCallback({ domain: d }, common.mustCall(function() {
+      makeCallback({ domain: d }, common.mustCall(() => {
         assert.strictEqual(latestWarning.name, 'DeprecationWarning');
         assert.strictEqual(latestWarning.code, 'DEP0097');
       }));
diff --git a/test/addons/make-callback-recurse/test.js b/test/addons/make-callback-recurse/test.js
index a93a0a4e01bfd7..4a540003acd8d1 100644
--- a/test/addons/make-callback-recurse/test.js
+++ b/test/addons/make-callback-recurse/test.js
@@ -71,7 +71,7 @@ assert.throws(() => {
     if (arg === 1) {
       // The tests are first run on bootstrap during LoadEnvironment() in
       // src/node.cc. Now run the tests through node::MakeCallback().
-      setImmediate(function() {
+      setImmediate(() => {
         makeCallback({}, common.mustCall(() => {
           verifyExecutionOrder(2);
         }));
diff --git a/test/addons/openssl-client-cert-engine/test.js b/test/addons/openssl-client-cert-engine/test.js
index 9e7d507b07b7ac..e843e4bf433bff 100644
--- a/test/addons/openssl-client-cert-engine/test.js
+++ b/test/addons/openssl-client-cert-engine/test.js
@@ -43,14 +43,14 @@ const server = https.createServer(serverOptions, common.mustCall((req, res) => {
     headers: {}
   };
 
-  const req = https.request(clientOptions, common.mustCall(function(response) {
+  const req = https.request(clientOptions, common.mustCall((response) => {
     let body = '';
     response.setEncoding('utf8');
-    response.on('data', function(chunk) {
+    response.on('data', (chunk) => {
       body += chunk;
     });
 
-    response.on('end', common.mustCall(function() {
+    response.on('end', common.mustCall(() => {
       assert.strictEqual(body, 'hello world');
       server.close();
     }));
diff --git a/test/addons/openssl-key-engine/test.js b/test/addons/openssl-key-engine/test.js
index 5c93e6263626bf..2cd7ddabc17095 100644
--- a/test/addons/openssl-key-engine/test.js
+++ b/test/addons/openssl-key-engine/test.js
@@ -45,14 +45,14 @@ const server = https.createServer(serverOptions, common.mustCall((req, res) => {
     headers: {}
   };
 
-  const req = https.request(clientOptions, common.mustCall(function(response) {
+  const req = https.request(clientOptions, common.mustCall((response) => {
     let body = '';
     response.setEncoding('utf8');
-    response.on('data', function(chunk) {
+    response.on('data', (chunk) => {
       body += chunk;
     });
 
-    response.on('end', common.mustCall(function() {
+    response.on('end', common.mustCall(() => {
       assert.strictEqual(body, 'hello world');
       server.close();
     }));
diff --git a/test/addons/repl-domain-abort/test.js b/test/addons/repl-domain-abort/test.js
index 2049fe6e6a23f5..f8e70ffce96e45 100644
--- a/test/addons/repl-domain-abort/test.js
+++ b/test/addons/repl-domain-abort/test.js
@@ -31,7 +31,7 @@ if (common.isWindows)
   buildPath = buildPath.replace(/\\/g, '/');
 let cb_ran = false;
 
-process.on('exit', function() {
+process.on('exit', () => {
   assert(cb_ran);
   console.log('ok');
 });
diff --git a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-ascii.js b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-ascii.js
index 5e3033db3ea193..55f50f524927e8 100644
--- a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-ascii.js
+++ b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-ascii.js
@@ -25,7 +25,7 @@ if (!binding.ensureAllocation(2 * kStringMaxLength))
   common.skip(skipMessage);
 
 const stringLengthHex = kStringMaxLength.toString(16);
-common.expectsError(function() {
+common.expectsError(() => {
   buf.toString('ascii');
 }, {
   message: `Cannot create a string longer than 0x${stringLengthHex} ` +
diff --git a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-base64.js b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-base64.js
index 400477034d0010..20d968787bf731 100644
--- a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-base64.js
+++ b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-base64.js
@@ -25,7 +25,7 @@ if (!binding.ensureAllocation(2 * kStringMaxLength))
   common.skip(skipMessage);
 
 const stringLengthHex = kStringMaxLength.toString(16);
-common.expectsError(function() {
+common.expectsError(() => {
   buf.toString('base64');
 }, {
   message: `Cannot create a string longer than 0x${stringLengthHex} ` +
diff --git a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-binary.js b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-binary.js
index ef5d6a21ed0042..f6ae5217ddf0ec 100644
--- a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-binary.js
+++ b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-binary.js
@@ -27,7 +27,7 @@ if (!binding.ensureAllocation(2 * kStringMaxLength))
   common.skip(skipMessage);
 
 const stringLengthHex = kStringMaxLength.toString(16);
-common.expectsError(function() {
+common.expectsError(() => {
   buf.toString('latin1');
 }, {
   message: `Cannot create a string longer than 0x${stringLengthHex} ` +
diff --git a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-hex.js b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-hex.js
index 844c8bcb335a87..fa7a47cf184cd1 100644
--- a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-hex.js
+++ b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-hex.js
@@ -25,7 +25,7 @@ if (!binding.ensureAllocation(2 * kStringMaxLength))
   common.skip(skipMessage);
 
 const stringLengthHex = kStringMaxLength.toString(16);
-common.expectsError(function() {
+common.expectsError(() => {
   buf.toString('hex');
 }, {
   message: `Cannot create a string longer than 0x${stringLengthHex} ` +
diff --git a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-utf8.js b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-utf8.js
index 15ec78b6c9ab1c..43c88bd49e7e15 100644
--- a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-utf8.js
+++ b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-utf8.js
@@ -27,9 +27,9 @@ if (!binding.ensureAllocation(2 * kStringMaxLength))
 
 const stringLengthHex = kStringMaxLength.toString(16);
 
-assert.throws(function() {
+assert.throws(() => {
   buf.toString();
-}, function(e) {
+}, (e) => {
   if (e.message !== 'Array buffer allocation failed') {
     common.expectsError({
       message: `Cannot create a string longer than 0x${stringLengthHex} ` +
@@ -43,7 +43,7 @@ assert.throws(function() {
   }
 });
 
-common.expectsError(function() {
+common.expectsError(() => {
   buf.toString('utf8');
 }, {
   message: `Cannot create a string longer than 0x${stringLengthHex} ` +
diff --git a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max.js b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max.js
index d65144e04d457c..8b419eb4362de0 100644
--- a/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max.js
+++ b/test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max.js
@@ -26,7 +26,7 @@ if (!binding.ensureAllocation(2 * kStringMaxLength))
 
 const stringLengthHex = kStringMaxLength.toString(16);
 
-common.expectsError(function() {
+common.expectsError(() => {
   buf.toString('utf16le');
 }, {
   message: `Cannot create a string longer than 0x${stringLengthHex} ` +