diff --git a/lib/bin.js b/lib/bin.js
index 7258893b9c391..f4b77120a2a84 100644
--- a/lib/bin.js
+++ b/lib/bin.js
@@ -17,7 +17,7 @@ function bin (args, silent, cb) {
   if (!silent) output(b)
   process.nextTick(cb.bind(this, null, b))
 
-  if (npm.config.get('global') && PATH.indexOf(b) === -1) {
+  if (npm.config.get('global') && !PATH.includes(b)) {
     npm.config.get('logstream').write('(not in PATH env variable)\n')
   }
 }
diff --git a/lib/build.js b/lib/build.js
index f8b3c4933ed1b..3919013896f05 100644
--- a/lib/build.js
+++ b/lib/build.js
@@ -121,9 +121,9 @@ function rebuildBundles (pkg, folder, cb) {
       // not a .folder, like .bin or .hooks
       return !file.match(/^[._-]/) &&
           // not some old 0.x style bundle
-          file.indexOf('@') === -1 &&
+          !file.includes('@') &&
           // either not a dep, or explicitly bundled
-          (deps.indexOf(file) === -1 || bundles.indexOf(file) !== -1)
+          (!deps.includes(file) || bundles.includes(file))
     }).map(function (file) {
       file = path.resolve(folder, 'node_modules', file)
       return function (cb) {
diff --git a/lib/completion.js b/lib/completion.js
index a682c134a7737..a0bbd63e50733 100644
--- a/lib/completion.js
+++ b/lib/completion.js
@@ -101,7 +101,7 @@ function completion (args, cb) {
 
   console.error(opts)
 
-  if (partialWords.slice(0, -1).indexOf('--') === -1) {
+  if (!partialWords.slice(0, -1).includes('--')) {
     if (word.charAt(0) === '-') return configCompl(opts, cb)
     if (words[w - 1] &&
         words[w - 1].charAt(0) === '-' &&
diff --git a/lib/config.js b/lib/config.js
index 5f9819879be23..5a569025b7407 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -143,7 +143,7 @@ function set (key, val, cb) {
     return unknown('', cb)
   }
   if (val === undefined) {
-    if (key.indexOf('=') !== -1) {
+    if (key.includes('=')) {
       var k = key.split('=')
       key = k.shift()
       val = k.join('=')
@@ -176,7 +176,7 @@ function sort (a, b) {
 }
 
 function publicVar (k) {
-  return !(k.charAt(0) === '_' || k.indexOf(':_') !== -1)
+  return !(k.charAt(0) === '_' || k.includes(':_'))
 }
 
 function getKeys (data) {
diff --git a/lib/config/core.js b/lib/config/core.js
index 36420b3450163..e5d7e83be9649 100644
--- a/lib/config/core.js
+++ b/lib/config/core.js
@@ -361,11 +361,11 @@ function parseField (f, k) {
 
   // type can be an array or single thing.
   var typeList = [].concat(types[k])
-  var isPath = typeList.indexOf(path) !== -1
-  var isBool = typeList.indexOf(Boolean) !== -1
-  var isString = typeList.indexOf(String) !== -1
-  var isUmask = typeList.indexOf(Umask) !== -1
-  var isNumber = typeList.indexOf(Number) !== -1
+  var isPath = typeList.includes(path)
+  var isBool = typeList.includes(Boolean)
+  var isString = typeList.includes(String)
+  var isUmask = typeList.includes(Umask)
+  var isNumber = typeList.includes(Number)
 
   f = ('' + f).trim()
 
diff --git a/lib/config/defaults.js b/lib/config/defaults.js
index e07da3aaf97f4..ae7ee428a08c5 100644
--- a/lib/config/defaults.js
+++ b/lib/config/defaults.js
@@ -45,8 +45,8 @@ nopt.invalidHandler = function (k, val, type) {
   log.warn('invalid config', k + '=' + JSON.stringify(val))
 
   if (Array.isArray(type)) {
-    if (type.indexOf(url) !== -1) type = url
-    else if (type.indexOf(path) !== -1) type = path
+    if (type.includes(url)) type = url
+    else if (type.includes(path)) type = path
   }
 
   switch (type) {
diff --git a/lib/help-search.js b/lib/help-search.js
index 475f305e49103..c2de0ef30f3d1 100644
--- a/lib/help-search.js
+++ b/lib/help-search.js
@@ -51,7 +51,7 @@ function searchFiles (args, files, cb) {
     // skip if no matches at all
     var match
     for (var a = 0, l = args.length; a < l && !match; a++) {
-      match = data.toLowerCase().indexOf(args[a].toLowerCase()) !== -1
+      match = data.toLowerCase().includes(args[a].toLowerCase())
     }
     if (!match) return
 
@@ -69,8 +69,7 @@ function searchFiles (args, files, cb) {
       match = false
       if (nextLine) {
         for (a = 0, ll = args.length; a < ll && !match; a++) {
-          match = nextLine.toLowerCase()
-            .indexOf(args[a].toLowerCase()) !== -1
+          match = nextLine.toLowerCase().includes(args[a].toLowerCase())
         }
         if (match) {
           // skip over the next line, and the line after it.
@@ -81,7 +80,7 @@ function searchFiles (args, files, cb) {
 
       match = false
       for (a = 0, ll = args.length; a < ll && !match; a++) {
-        match = line.toLowerCase().indexOf(args[a].toLowerCase()) !== -1
+        match = line.toLowerCase().includes(args[a].toLowerCase())
       }
       if (match) {
         // skip over the next line
diff --git a/lib/help.js b/lib/help.js
index 61f1f3f94cc66..2f95d11ce5ef3 100644
--- a/lib/help.js
+++ b/lib/help.js
@@ -50,7 +50,7 @@ function help (args, cb) {
   }
 
   // npm apihelp <section>: Prefer section 3 over section 1
-  var apihelp = argv.length && argv[0].indexOf('api') !== -1
+  var apihelp = argv.length && argv[0].includes('api')
   var pref = apihelp ? [3, 1, 5, 7] : [1, 3, 5, 7]
   if (argnum) {
     pref = [ argnum ].concat(pref.filter(function (n) {
diff --git a/lib/install.js b/lib/install.js
index 378ada7b05c06..9b66eacccc3c5 100644
--- a/lib/install.js
+++ b/lib/install.js
@@ -67,7 +67,7 @@ install.completion = function (opts, cb) {
           null,
           {
             fullPath: fullPath,
-            isPackage: contents.indexOf('package.json') !== -1
+            isPackage: contents.includes('package.json')
           }
         )
       })
diff --git a/lib/install/diff-trees.js b/lib/install/diff-trees.js
index 147aa9b8e74f3..3a83eff264793 100644
--- a/lib/install/diff-trees.js
+++ b/lib/install/diff-trees.js
@@ -168,7 +168,7 @@ var sortActions = module.exports.sortActions = function (differences) {
 
   // safety net, anything excluded above gets tacked on the end
   differences.forEach((_) => {
-    if (sorted.indexOf(_) === -1) sorted.push(_)
+    if (!sorted.includes(_)) sorted.push(_)
   })
 
   return sorted
diff --git a/lib/link.js b/lib/link.js
index e05526c4080d3..acf57c700b27c 100644
--- a/lib/link.js
+++ b/lib/link.js
@@ -87,7 +87,7 @@ function linkInstall (pkgs, cb) {
 
     // if it's a folder, a random not-installed thing, or not a scoped package,
     // then link or install it first
-    if (pkg[0] !== '@' && (pkg.indexOf('/') !== -1 || pkg.indexOf('\\') !== -1)) {
+    if (pkg[0] !== '@' && (pkg.includes('/') || pkg.includes('\\'))) {
       return fs.lstat(path.resolve(pkg), function (er, st) {
         if (er || !st.isDirectory()) {
           npm.commands.install(t, pkg, n)
diff --git a/lib/ls.js b/lib/ls.js
index 78a2b1d791c7d..0913166d42948 100644
--- a/lib/ls.js
+++ b/lib/ls.js
@@ -46,7 +46,7 @@ function ls (args, silent, cb) {
 }
 
 function inList (list, value) {
-  return list.indexOf(value) !== -1
+  return list.includes(value)
 }
 
 var lsFromTree = ls.fromTree = function (dir, physicalTree, args, silent, cb) {
@@ -125,7 +125,7 @@ function pruneNestedExtraneous (data, visited) {
   for (var i in data.dependencies) {
     if (data.dependencies[i].extraneous) {
       data.dependencies[i].dependencies = {}
-    } else if (visited.indexOf(data.dependencies[i]) === -1) {
+    } else if (!visited.includes(data.dependencies[i])) {
       pruneNestedExtraneous(data.dependencies[i], visited)
     }
   }
diff --git a/lib/npm.js b/lib/npm.js
index 74ef6ad2c6e74..fc1a90fa0954f 100644
--- a/lib/npm.js
+++ b/lib/npm.js
@@ -94,13 +94,13 @@
 
   var littleGuys = [ 'isntall', 'verison' ]
   var fullList = cmdList.concat(aliasNames).filter(function (c) {
-    return plumbing.indexOf(c) === -1
+    return !plumbing.includes(c)
   })
   var abbrevs = abbrev(fullList)
 
   // we have our reasons
   fullList = npm.fullList = fullList.filter(function (c) {
-    return littleGuys.indexOf(c) === -1
+    return !littleGuys.includes(c)
   })
 
   var registryRefer
@@ -162,7 +162,7 @@
 
       return commandCache[a]
     },
-    enumerable: fullList.indexOf(c) !== -1,
+    enumerable: fullList.includes(c),
     configurable: true })
 
     // make css-case commands callable via camelCase as well
@@ -186,7 +186,7 @@
         return '-' + m.toLowerCase()
       })
     }
-    if (plumbing.indexOf(c) !== -1) return c
+    if (plumbing.includes(c)) return c
     var a = abbrevs[c]
     while (aliases[a]) {
       a = aliases[a]
diff --git a/lib/outdated.js b/lib/outdated.js
index 5b84ae35587c8..5c0c19480c3c5 100644
--- a/lib/outdated.js
+++ b/lib/outdated.js
@@ -352,7 +352,7 @@ function shouldUpdate (args, tree, dep, has, req, depth, pkgpath, opts, cb, type
       cb)
   }
 
-  if (args.length && args.indexOf(dep) === -1) return skip()
+  if (args.length && !args.includes(dep)) return skip()
 
   if (tree.isLink && req == null) return skip()
 
diff --git a/lib/owner.js b/lib/owner.js
index a64cb5e14ccef..a565b0500f04f 100644
--- a/lib/owner.js
+++ b/lib/owner.js
@@ -46,7 +46,7 @@ owner.completion = function (opts, cb) {
             return npmFetch.json(byUser, opts).then(d => {
               return d[theUser].filter(
                 // kludge for server adminery.
-                p => un === 'isaacs' || d[un].indexOf(p) === -1
+                p => un === 'isaacs' || !d[un].includes(p)
               )
             })
           }
@@ -59,7 +59,7 @@ owner.completion = function (opts, cb) {
             return npmFetch.json(byUser, opts).then(d => {
               var mine = d[un] || []
               var theirs = d[theUser] || []
-              return mine.filter(p => theirs.indexOf(p) === -1)
+              return mine.filter(p => !theirs.includes(p))
             })
           } else {
             // just list all users who aren't me.
diff --git a/lib/profile.js b/lib/profile.js
index 7ce9cb5cce5df..8d03ee57d8cd1 100644
--- a/lib/profile.js
+++ b/lib/profile.js
@@ -150,7 +150,7 @@ function set (args) {
       'npm profile set password\n' +
       'Do not include your current or new passwords on the command line.'))
   }
-  if (writableProfileKeys.indexOf(prop) === -1) {
+  if (!writableProfileKeys.includes(prop)) {
     return Promise.reject(Error(`"${prop}" is not a property we can set. Valid properties are: ` + writableProfileKeys.join(', ')))
   }
   return BB.try(() => {
diff --git a/lib/prune.js b/lib/prune.js
index 010e471e4b328..3de9609120ca5 100644
--- a/lib/prune.js
+++ b/lib/prune.js
@@ -50,7 +50,7 @@ Pruner.prototype.loadAllDepsIntoIdealTree = function (cb) {
     return moduleName(child)
   }
   function matchesArg (name) {
-    return self.args.length === 0 || self.args.indexOf(name) !== -1
+    return self.args.length === 0 || self.args.includes(name)
   }
   function nameObj (name) {
     return {name: name}
diff --git a/lib/run-script.js b/lib/run-script.js
index 476591c051e73..bc57e5952fa3d 100644
--- a/lib/run-script.js
+++ b/lib/run-script.js
@@ -31,7 +31,7 @@ runScript.completion = function (opts, cb) {
       if (er) d = {}
       var scripts = Object.keys(d.scripts || {})
       console.error('local scripts', scripts)
-      if (scripts.indexOf(argv[2]) !== -1) return cb()
+      if (scripts.includes(argv[2])) return cb()
       // ok, try to find out which package it was, then
       var pref = npm.config.get('global') ? npm.config.get('prefix')
         : npm.localPrefix
@@ -85,7 +85,7 @@ function list (cb) {
     var scripts = []
     var runScripts = []
     allScripts.forEach(function (script) {
-      if (cmdList.indexOf(script) !== -1) scripts.push(script)
+      if (cmdList.includes(script)) scripts.push(script)
       else runScripts.push(script)
     })
 
diff --git a/lib/search/package-filter.js b/lib/search/package-filter.js
index 892adb08c96a5..ded46bbe0cbad 100644
--- a/lib/search/package-filter.js
+++ b/lib/search/package-filter.js
@@ -37,5 +37,5 @@ function match (words, pattern) {
     pattern = new RegExp(pattern.substr(1, pattern.length - 1))
     return words.match(pattern)
   }
-  return words.indexOf(pattern) !== -1
+  return words.includes(pattern)
 }
diff --git a/lib/update.js b/lib/update.js
index fdb934fac6730..9956debfeb52e 100644
--- a/lib/update.js
+++ b/lib/update.js
@@ -61,7 +61,7 @@ function update_ (args) {
       const isTransitive = !(ww.dep.requiredBy || []).some((p) => p.isTop)
       const key = where + ':' + String(isTransitive)
       if (!toInstall[key]) toInstall[key] = {where: where, opts: {saveOnlyLock: isTransitive}, what: []}
-      if (toInstall[key].what.indexOf(ww.what) === -1) toInstall[key].what.push(ww.what)
+      if (!toInstall[key].what.includes(ww.what)) toInstall[key].what.push(ww.what)
     })
     return Bluebird.each(Object.keys(toInstall), (key) => {
       const deps = toInstall[key]
diff --git a/lib/utils/error-message.js b/lib/utils/error-message.js
index 12f304d1e894a..fa6a7b7f5c21d 100644
--- a/lib/utils/error-message.js
+++ b/lib/utils/error-message.js
@@ -157,7 +157,7 @@ function errorMessage (er) {
         // npm ERR! code E401
         // npm ERR! Unable to authenticate, need: Basic
         const auth = (er.headers && er.headers['www-authenticate'] && er.headers['www-authenticate'].map((au) => au.split(/,\s*/))[0]) || []
-        if (auth.indexOf('Bearer') !== -1) {
+        if (auth.includes('Bearer')) {
           short.push(['', 'Unable to authenticate, your authentication token seems to be invalid.'])
           detail.push([
             '',
@@ -166,7 +166,7 @@ function errorMessage (er) {
               '    npm login'
             ].join('\n')
           ])
-        } else if (auth.indexOf('Basic') !== -1) {
+        } else if (auth.includes('Basic')) {
           short.push(['', 'Incorrect or missing password.'])
           detail.push([
             '',
diff --git a/lib/utils/open-url.js b/lib/utils/open-url.js
index e1ed2b3fab76d..fe4534ef83e06 100644
--- a/lib/utils/open-url.js
+++ b/lib/utils/open-url.js
@@ -17,7 +17,7 @@ module.exports = function open (url, errMsg, cb, browser = npm.config.get('brows
     output(alternateMsg)
   }
 
-  const skipBrowser = process.argv.indexOf('--no-browser') > -1
+  const skipBrowser = process.argv.includes('--no-browser')
 
   if (skipBrowser) {
     printAlternateMsg()
diff --git a/lib/version.js b/lib/version.js
index 6619a8ba9d0d7..672bbf4a5051e 100644
--- a/lib/version.js
+++ b/lib/version.js
@@ -74,7 +74,7 @@ function parseLastGitTag (cb) {
   var options = { env: process.env }
   git.whichAndExec(['describe', '--abbrev=0'], options, function (er, stdout) {
     if (er) {
-      if (er.message.indexOf('No names found') !== -1) return cb(new Error('No tags found'))
+      if (er.message.includes('No names found')) return cb(new Error('No tags found'))
       return cb(er)
     }
 
diff --git a/lib/view.js b/lib/view.js
index a16884e25f647..2904a882c2b9d 100644
--- a/lib/view.js
+++ b/lib/view.js
@@ -56,7 +56,7 @@ view.completion = function (opts, cb) {
     if (!d) return f
     pref = pref || []
     Object.keys(d).forEach(function (k) {
-      if (k.charAt(0) === '_' || k.indexOf('.') !== -1) return
+      if (k.charAt(0) === '_' || k.includes('.')) return
       const p = pref.concat(k).join('.')
       f.push(p)
       if (Array.isArray(d[k])) {
@@ -162,7 +162,7 @@ function fetchAndRead (nv, args, silent, opts, cb) {
     if (!args.length) args = ['']
 
     // remove readme unless we asked for it
-    if (args.indexOf('readme') === -1) {
+    if (!args.includes('readme')) {
       delete data.readme
     }
 
@@ -170,7 +170,7 @@ function fetchAndRead (nv, args, silent, opts, cb) {
       if (semver.satisfies(v, version, true)) {
         args.forEach(function (args) {
           // remove readme unless we asked for it
-          if (args.indexOf('readme') !== -1) {
+          if (args.includes('readme')) {
             delete versions[v].readme
           }
           results.push(showFields(data, versions[v], args))
@@ -447,7 +447,7 @@ function printData (data, name, opts, cb) {
       }
       if (!opts.json) {
         if (f && includeFields) f += ' = '
-        if (d.indexOf('\n') !== -1) d = ' \n' + d
+        if (d.includes('\n')) d = ' \n' + d
         msg += (includeVersions ? name + '@' + v + ' ' : '') +
                (includeFields ? f : '') + d + '\n'
       }
diff --git a/test/tap/00-verify-bundle-deps.js b/test/tap/00-verify-bundle-deps.js
index 75ea81c593e76..88507492778a1 100644
--- a/test/tap/00-verify-bundle-deps.js
+++ b/test/tap/00-verify-bundle-deps.js
@@ -7,7 +7,7 @@ var bundled = manifest.bundleDependencies
 test('all deps are bundled deps or dev deps', function (t) {
   deps.forEach(function (name) {
     t.assert(
-      bundled.indexOf(name) !== -1,
+      bundled.includes(name),
       name + ' is in bundledDependencies'
     )
   })
diff --git a/test/tap/config-meta.js b/test/tap/config-meta.js
index a98d5e6c4dabd..c6b83ad8b8f56 100644
--- a/test/tap/config-meta.js
+++ b/test/tap/config-meta.js
@@ -72,7 +72,7 @@ test('get lines', function (t) {
               line: i
             }
           }
-        } else if (exceptions.indexOf(f) === -1 && f.indexOf('.cache') === -1) {
+        } else if (!exceptions.includes(f) && !f.includes('.cache')) {
           t.fail('non-string-literal config used in ' + f + ':' + i)
         }
       })
@@ -105,8 +105,8 @@ test('check configs', function (t) {
     if (CONFS[c1].file.indexOf(lib) === 0) {
       t.ok(DOC[c1], 'should be documented ' + c1 + ' ' +
            CONFS[c1].file + ':' + CONFS[c1].line)
-      t.ok(types.indexOf(c1) !== -1, 'should be defined in npmconf ' + c1)
-      t.ok(defaults.indexOf(c1) !== -1, 'should have default in npmconf ' + c1)
+      t.ok(types.includes(c1), 'should be defined in npmconf ' + c1)
+      t.ok(defaults.includes(c1), 'should have default in npmconf ' + c1)
     }
   }
 
diff --git a/test/tap/gist-short-shortcut-package.js b/test/tap/gist-short-shortcut-package.js
index 601d53a827666..3f216eba853ef 100644
--- a/test/tap/gist-short-shortcut-package.js
+++ b/test/tap/gist-short-shortcut-package.js
@@ -33,7 +33,7 @@ test('gist-short-shortcut-package', function (t) {
     'child_process': {
       'execFile': function (cmd, args, options, cb) {
         process.nextTick(function () {
-          if (args.indexOf('clone') === -1) return cb(null, '', '')
+          if (!args.includes('clone')) return cb(null, '', '')
           var cloneUrl = cloneUrls.shift()
           if (cloneUrl) {
             t.is(args[args.length - 2], cloneUrl[0], cloneUrl[1])
diff --git a/test/tap/gist-short-shortcut.js b/test/tap/gist-short-shortcut.js
index 82c9ae17502dd..2f5b4f8c13cbd 100644
--- a/test/tap/gist-short-shortcut.js
+++ b/test/tap/gist-short-shortcut.js
@@ -30,7 +30,7 @@ test('gist-shortcut', function (t) {
     'child_process': {
       'execFile': function (cmd, args, options, cb) {
         process.nextTick(function () {
-          if (args.indexOf('clone') === -1) return cb(null, '', '')
+          if (!args.includes('clone')) return cb(null, '', '')
           var cloneUrl = cloneUrls.shift()
           if (cloneUrl) {
             t.is(args[args.length - 2], cloneUrl[0], cloneUrl[1])
diff --git a/test/tap/gist-shortcut-package.js b/test/tap/gist-shortcut-package.js
index 28e57357cc393..ee902f40cfa41 100644
--- a/test/tap/gist-shortcut-package.js
+++ b/test/tap/gist-shortcut-package.js
@@ -28,7 +28,7 @@ test('gist-shortcut-package', function (t) {
     'child_process': {
       'execFile': function (cmd, args, options, cb) {
         process.nextTick(function () {
-          if (args.indexOf('clone') === -1) return cb(null, '', '')
+          if (!args.includes('clone')) return cb(null, '', '')
           var cloneUrl = cloneUrls.shift()
           if (cloneUrl) {
             t.is(args[args.length - 2], cloneUrl[0], cloneUrl[1])
diff --git a/test/tap/gist-shortcut.js b/test/tap/gist-shortcut.js
index ca86d6bc55058..aa0ad5ce1e674 100644
--- a/test/tap/gist-shortcut.js
+++ b/test/tap/gist-shortcut.js
@@ -29,7 +29,7 @@ test('gist-shortcut', function (t) {
     'child_process': {
       'execFile': function (cmd, args, options, cb) {
         process.nextTick(function () {
-          if (args.indexOf('clone') === -1) return cb(null, '', '')
+          if (!args.includes('clone')) return cb(null, '', '')
           var cloneUrl = cloneUrls.shift()
           if (cloneUrl) {
             t.is(args[args.length - 2], cloneUrl[0], cloneUrl[1])
diff --git a/test/tap/github-shortcut-package.js b/test/tap/github-shortcut-package.js
index 444520308a245..40852569ec508 100644
--- a/test/tap/github-shortcut-package.js
+++ b/test/tap/github-shortcut-package.js
@@ -32,7 +32,7 @@ test('github-shortcut-package', function (t) {
     'child_process': {
       'execFile': function (cmd, args, options, cb) {
         process.nextTick(function () {
-          if (args.indexOf('clone') === -1) return cb(null, '', '')
+          if (!args.includes('clone')) return cb(null, '', '')
           var cloneUrl = cloneUrls.shift()
           if (cloneUrl) {
             t.is(args[args.length - 2], cloneUrl[0], cloneUrl[1])
diff --git a/test/tap/gitlab-shortcut-package.js b/test/tap/gitlab-shortcut-package.js
index 9b431ff7b66f0..40e7f686950dc 100644
--- a/test/tap/gitlab-shortcut-package.js
+++ b/test/tap/gitlab-shortcut-package.js
@@ -31,7 +31,7 @@ test('gitlab-shortcut-package', function (t) {
     'child_process': {
       'execFile': function (cmd, args, options, cb) {
         process.nextTick(function () {
-          if (args.indexOf('clone') === -1) return cb(null, '', '')
+          if (!args.includes('clone')) return cb(null, '', '')
           var cloneUrl = cloneUrls.shift()
           if (cloneUrl) {
             t.is(args[args.length - 2], cloneUrl[0], cloneUrl[1])
diff --git a/test/tap/gitlab-shortcut.js b/test/tap/gitlab-shortcut.js
index 344311b45f26c..2b50d0eb48a0f 100644
--- a/test/tap/gitlab-shortcut.js
+++ b/test/tap/gitlab-shortcut.js
@@ -28,7 +28,7 @@ test('gitlab-shortcut', function (t) {
     'child_process': {
       'execFile': function (cmd, args, options, cb) {
         process.nextTick(function () {
-          if (args.indexOf('clone') === -1) return cb(null, '', '')
+          if (!args.includes('clone')) return cb(null, '', '')
           var cloneUrl = cloneUrls.shift()
           if (cloneUrl) {
             t.is(args[args.length - 2], cloneUrl[0], cloneUrl[1])
diff --git a/test/tap/version-from-git.js b/test/tap/version-from-git.js
index e63865a73378a..087402e6b3d5a 100644
--- a/test/tap/version-from-git.js
+++ b/test/tap/version-from-git.js
@@ -39,7 +39,7 @@ test('npm version from-git with a valid tag creates a new commit', function (t)
   function checkCommit (er, log, stderr) {
     t.ifError(er, 'git log ran without issue')
     t.notOk(stderr, 'no error output')
-    t.ok(log.indexOf(version) !== -1, 'commit was created')
+    t.ok(log.includes(version), 'commit was created')
     t.end()
   }
 })
@@ -95,8 +95,8 @@ test('npm version from-git strips tag-version-prefix', function (t) {
   function checkCommit (er, log, stderr) {
     t.ifError(er, 'git log ran without issue')
     t.notOk(stderr, 'no error output')
-    t.ok(log.indexOf(tag) === -1, 'commit should not include prefix')
-    t.ok(log.indexOf(version) !== -1, 'commit should include version')
+    t.ok(!log.includes(tag), 'commit should not include prefix')
+    t.ok(log.includes(version), 'commit should include version')
     t.end()
   }
 })
@@ -128,7 +128,7 @@ test('npm version from-git only strips tag-version-prefix if it is a prefix', fu
   function checkCommit (er, log, stderr) {
     t.ifError(er, 'git log ran without issue')
     t.notOk(stderr, 'no error output')
-    t.ok(log.indexOf(version) !== -1, 'commit should include the full version')
+    t.ok(log.includes(version), 'commit should include the full version')
     t.end()
   }
 })