diff --git a/test/helpers/helpers.js b/test/helpers/helpers.js
index 25f0f4b63c..5395a5310f 100644
--- a/test/helpers/helpers.js
+++ b/test/helpers/helpers.js
@@ -2,13 +2,13 @@ const marked = require('../../');
 const HtmlDiffer = require('@markedjs/html-differ').HtmlDiffer;
 const htmlDiffer = new HtmlDiffer({ignoreSelfClosingSlash: true});
 
-beforeEach(function () {
+beforeEach(() => {
   marked.setOptions(marked.getDefaults());
 
   jasmine.addMatchers({
-    toRender: function () {
+    toRender: () => {
       return {
-        compare: function (spec, expected) {
+        compare: (spec, expected) => {
           const result = {};
           const actual = marked(spec.markdown, spec.options);
           result.pass = htmlDiffer.isEqual(expected, actual);
diff --git a/test/specs/original/specs-spec.js b/test/specs/original/specs-spec.js
index d0869dd472..a3a1df437c 100644
--- a/test/specs/original/specs-spec.js
+++ b/test/specs/original/specs-spec.js
@@ -1,6 +1,6 @@
 var specTests = require('../../');
 
-it('should run spec tests', function () {
+it('should run spec tests', () => {
   // hide output
   spyOn(console, 'log');
   if (!specTests(['', '', '--stop'])) {
diff --git a/test/specs/run-spec.js b/test/specs/run-spec.js
index 809ae10ce2..b827a0dcf0 100644
--- a/test/specs/run-spec.js
+++ b/test/specs/run-spec.js
@@ -8,14 +8,14 @@ function runSpecs(title, file, options) {
     return obj;
   }, {});
 
-  describe(title, function() {
+  describe(title, () => {
     Object.keys(specs).forEach(section => {
-      describe(section, function() {
-        specs[section].forEach(function(spec) {
+      describe(section, () => {
+        specs[section].forEach((spec) => {
           if (options) {
             spec.options = Object.assign({}, options, (spec.options || {}));
           }
-          (spec.only ? fit : it)('should ' + (spec.shouldFail ? 'fail' : 'pass') + ' example ' + spec.example, function() {
+          (spec.only ? fit : it)('should ' + (spec.shouldFail ? 'fail' : 'pass') + ' example ' + spec.example, () => {
             if (spec.shouldFail) {
               expect(spec).not.toRender(spec.html);
             } else {
diff --git a/test/unit/marked-spec.js b/test/unit/marked-spec.js
index c365e8599c..994c5dc8d7 100644
--- a/test/unit/marked-spec.js
+++ b/test/unit/marked-spec.js
@@ -1,41 +1,41 @@
 var marked = require('../../lib/marked.js');
 
-describe('Test heading ID functionality', function() {
-  it('should add id attribute by default', function() {
+describe('Test heading ID functionality', () => {
+  it('should add id attribute by default', () => {
     var renderer = new marked.Renderer();
     var slugger = new marked.Slugger();
     var header = renderer.heading('test', 1, 'test', slugger);
     expect(header).toBe('<h1 id="test">test</h1>\n');
   });
 
-  it('should NOT add id attribute when options set false', function() {
+  it('should NOT add id attribute when options set false', () => {
     var renderer = new marked.Renderer({ headerIds: false });
     var header = renderer.heading('test', 1, 'test');
     expect(header).toBe('<h1>test</h1>\n');
   });
 });
 
-describe('Test slugger functionality', function() {
-  it('should use lowercase slug', function() {
+describe('Test slugger functionality', () => {
+  it('should use lowercase slug', () => {
     var slugger = new marked.Slugger();
     expect(slugger.slug('Test')).toBe('test');
   });
 
-  it('should be unique to avoid collisions 1280', function() {
+  it('should be unique to avoid collisions 1280', () => {
     var slugger = new marked.Slugger();
     expect(slugger.slug('test')).toBe('test');
     expect(slugger.slug('test')).toBe('test-1');
     expect(slugger.slug('test')).toBe('test-2');
   });
 
-  it('should be unique when slug ends with number', function() {
+  it('should be unique when slug ends with number', () => {
     var slugger = new marked.Slugger();
     expect(slugger.slug('test 1')).toBe('test-1');
     expect(slugger.slug('test')).toBe('test');
     expect(slugger.slug('test')).toBe('test-2');
   });
 
-  it('should be unique when slug ends with hyphen number', function() {
+  it('should be unique when slug ends with hyphen number', () => {
     var slugger = new marked.Slugger();
     expect(slugger.slug('foo')).toBe('foo');
     expect(slugger.slug('foo')).toBe('foo-1');
@@ -44,24 +44,24 @@ describe('Test slugger functionality', function() {
     expect(slugger.slug('foo')).toBe('foo-2');
   });
 
-  it('should allow non-latin chars', function() {
+  it('should allow non-latin chars', () => {
     var slugger = new marked.Slugger();
     expect(slugger.slug('привет')).toBe('привет');
   });
 
-  it('should remove ampersands 857', function() {
+  it('should remove ampersands 857', () => {
     var slugger = new marked.Slugger();
     expect(slugger.slug('This & That Section')).toBe('this--that-section');
   });
 
-  it('should remove periods', function() {
+  it('should remove periods', () => {
     var slugger = new marked.Slugger();
     expect(slugger.slug('file.txt')).toBe('filetxt');
   });
 });
 
-describe('Test paragraph token type', function () {
-  it('should use the "paragraph" type on top level', function () {
+describe('Test paragraph token type', () => {
+  it('should use the "paragraph" type on top level', () => {
     const md = 'A Paragraph.\n\n> A blockquote\n\n- list item\n';
 
     const tokens = marked.lexer(md);