diff --git a/.travis.yml b/.travis.yml
index 51d8f8d..28e1328 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,7 +4,6 @@ node_js:
 - '10'
 - '8'
 - '6'
-- '4'
 
 script: npm test
 
diff --git a/package.json b/package.json
index 7f0ae79..0a79692 100644
--- a/package.json
+++ b/package.json
@@ -83,10 +83,6 @@
       "node",
       "mocha"
     ],
-    "rules": {
-      "prefer-destructuring": 0,
-      "prefer-rest-params": 0
-    },
     "prettier": true
   },
   "config": {
diff --git a/src/reporter.js b/src/reporter.js
index 8c9e6ba..bd825c9 100644
--- a/src/reporter.js
+++ b/src/reporter.js
@@ -1,5 +1,3 @@
-'use strict';
-
 const istanbul = require('istanbul-api');
 const util = require('./util');
 
@@ -187,6 +185,7 @@ function CoverageIstanbulReporter(baseReporterDecorator, logger, config) {
 
   const baseReporterOnRunComplete = this.onRunComplete;
   this.onRunComplete = function(browsers, results) {
+    // eslint-disable-next-line prefer-rest-params
     baseReporterOnRunComplete.apply(this, arguments);
 
     if (coverageConfig.combineBrowserReports) {
diff --git a/src/util.js b/src/util.js
index 315fa14..07c8509 100644
--- a/src/util.js
+++ b/src/util.js
@@ -1,5 +1,3 @@
-'use strict';
-
 const path = require('path');
 const minimatch = require('minimatch');
 
@@ -23,7 +21,7 @@ function fixWebpackFilePath(filePath) {
 }
 
 function fixWebpackSourcePaths(sourceMap, webpackConfig) {
-  let sourceRoot = sourceMap.sourceRoot;
+  let { sourceRoot } = sourceMap;
   // Fix for https://github.com/mattlewis92/karma-coverage-istanbul-reporter/issues/32
   // The sourceRoot is relative to the project directory and not an absolute path, so add the webpack context to it if set
   if (
diff --git a/test/reporter.spec.js b/test/reporter.spec.js
index ade2ba2..a417eab 100644
--- a/test/reporter.spec.js
+++ b/test/reporter.spec.js
@@ -5,9 +5,9 @@ const chai = require('chai');
 const karma = require('karma');
 const rimraf = require('rimraf');
 const karmaCoverageIstanbulReporter = require('../src/reporter');
-const OUTPUT_LOG_FILE = require('./karma.conf').OUTPUT_LOG_FILE;
+const { OUTPUT_LOG_FILE } = require('./karma.conf');
 
-const expect = chai.expect;
+const { expect } = chai;
 const OUTPUT_PATH = path.join(__dirname, 'fixtures', 'outputs');
 const OUTPUT_FILE = path.join(OUTPUT_PATH, 'coverage-summary.json');
 const fileReadTimeout = 300;
diff --git a/test/util.spec.js b/test/util.spec.js
index 2b4e661..7ad3635 100644
--- a/test/util.spec.js
+++ b/test/util.spec.js
@@ -1,5 +1,5 @@
-const expect = require('chai').expect;
-const fixWebpackSourcePaths = require('../src/util').fixWebpackSourcePaths;
+const { expect } = require('chai');
+const { fixWebpackSourcePaths } = require('../src/util');
 
 const originalPlatform = process.platform;