diff --git a/.eslintrc.js b/.eslintrc.js
index 7028f3786e..e7c19c939e 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -62,14 +62,14 @@ module.exports = {
         'prefer-destructuring': 'off',
         'prefer-template': 'off',
         'spaced-comment': ['error', 'always', {
-            line: {
-                markers: ['/'],
-                exceptions: ['-', '+'],
-            },
             block: {
-                markers: ['!'],
-                exceptions: ['*'],
                 balanced: true,
+                exceptions: ['*'],
+                markers: ['!'],
+            },
+            line: {
+                exceptions: ['-', '+'],
+                markers: ['/'],
             },
         }],
         strict: 'off',
diff --git a/gulpfile.js b/gulpfile.js
index aff1d1cf4f..78a1b95190 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -2,7 +2,7 @@
  *           Set-up
  *******************************/
 
-var
+let
     gulp   = require('gulp'),
 
     // read user config to know what task to load
diff --git a/tasks/README.md b/tasks/README.md
index c602e22234..89e4d414c6 100644
--- a/tasks/README.md
+++ b/tasks/README.md
@@ -10,8 +10,6 @@
 These tasks can be imported into your own gulpfile allowing you to avoid using Semantic's build tools
 
 ```javascript
-var
-  watch = require('path/to/semantic/tasks/watch')
-;
+const watch = require('path/to/semantic/tasks/watch');
 gulp.task('watch ui', watch);
 ```
diff --git a/tasks/admin/components/create.js b/tasks/admin/components/create.js
index b8d727afd5..d105831c1f 100644
--- a/tasks/admin/components/create.js
+++ b/tasks/admin/components/create.js
@@ -14,7 +14,7 @@
   * create meteor.js file
 */
 
-var
+let
     gulp            = require('gulp'),
 
     // node dependencies
@@ -41,20 +41,20 @@ var
 ;
 
 module.exports = function (callback) {
-    var
+    let
         stream,
         index,
         tasks = []
     ;
 
     for (index in release.components) {
-        var
+        let
             component = release.components[index]
     ;
 
         // streams... designed to save time and make coding fun...
         (function (component) {
-            var
+            let
                 outputDirectory      = path.join(release.outputRoot, component),
                 isJavascript         = fs.existsSync(output.compressed + component + '.js'),
                 isCSS                = fs.existsSync(output.compressed + component + '.css'),
@@ -266,7 +266,7 @@ module.exports = function (callback) {
 
             // Creates meteor package.js
             function createMeteorPackage() {
-                var
+                let
                     filenames = ''
                 ;
 
diff --git a/tasks/admin/components/init.js b/tasks/admin/components/init.js
index c4deb53897..59b7c3d138 100644
--- a/tasks/admin/components/init.js
+++ b/tasks/admin/components/init.js
@@ -12,7 +12,7 @@
 
 */
 
-var
+let
     gulp      = require('gulp'),
 
     // node dependencies
@@ -38,7 +38,7 @@ var
 ;
 
 module.exports = function (callback) {
-    var
+    let
         index = -1,
         total = release.components.length,
         timer,
@@ -62,7 +62,7 @@ module.exports = function (callback) {
             return;
         }
 
-        var
+        let
             component            = release.components[index],
             outputDirectory      = path.resolve(release.outputRoot + component),
             capitalizedComponent = component.charAt(0).toUpperCase() + component.slice(1),
diff --git a/tasks/admin/components/update.js b/tasks/admin/components/update.js
index a3acd8341f..986980ff22 100644
--- a/tasks/admin/components/update.js
+++ b/tasks/admin/components/update.js
@@ -12,7 +12,7 @@
 
 */
 
-var
+let
     gulp           = require('gulp'),
 
     // node dependencies
@@ -36,7 +36,7 @@ var
 ;
 
 module.exports = function (callback) {
-    var
+    let
         index = -1,
         total = release.components.length,
         timer,
@@ -59,7 +59,7 @@ module.exports = function (callback) {
             return;
         }
 
-        var
+        let
             component            = release.components[index],
             outputDirectory      = path.resolve(path.join(release.outputRoot, component)),
             capitalizedComponent = component.charAt(0).toUpperCase() + component.slice(1),
diff --git a/tasks/admin/distributions/create.js b/tasks/admin/distributions/create.js
index 921f7387ac..86d6837255 100644
--- a/tasks/admin/distributions/create.js
+++ b/tasks/admin/distributions/create.js
@@ -9,7 +9,7 @@
   * update package.json file
 */
 
-var
+let
     gulp            = require('gulp'),
 
     // node dependencies
@@ -35,20 +35,20 @@ var
 ;
 
 module.exports = function (callback) {
-    var
+    let
         stream,
         index,
         tasks = []
     ;
 
     for (index in release.distributions) {
-        var
+        let
             distribution = release.distributions[index]
     ;
 
         // streams... designed to save time and make coding fun...
         (function (distribution) {
-            var
+            let
                 distLowerCase   = distribution.toLowerCase(),
                 outputDirectory = path.join(release.outputRoot, distLowerCase),
                 packageFile     = path.join(outputDirectory, release.files.npm),
@@ -87,7 +87,7 @@ module.exports = function (callback) {
                     files = []
                 ;
                 list.forEach(function (file) {
-                    var
+                    let
                         isOmitted = (omitted.indexOf(file) > -1),
                         filePath  = path.join(dir, file),
                         stat      = fs.statSync(filePath)
@@ -106,8 +106,8 @@ module.exports = function (callback) {
 
             // spaces out list correctly
             createList = function (files) {
-                var filenames = '';
-                for (var file in files) {
+                let filenames = '';
+                for (let file in files) {
                     if (file == (files.length - 1)) {
                         filenames += "'" + files[file] + "'";
                     } else {
@@ -119,7 +119,7 @@ module.exports = function (callback) {
             };
 
             tasks.push(function () {
-                var
+                let
                     files     = gatherFiles(outputDirectory),
                     filenames = createList(files)
                 ;
@@ -135,7 +135,7 @@ module.exports = function (callback) {
 
             if (distribution == 'CSS') {
                 tasks.push(function () {
-                    var
+                    let
                         themes,
                         components,
                         releases
@@ -154,7 +154,7 @@ module.exports = function (callback) {
                 });
             } else if (distribution == 'LESS') {
                 tasks.push(function () {
-                    var
+                    let
                         definitions,
                         themeImport,
                         themeConfig,
diff --git a/tasks/admin/distributions/init.js b/tasks/admin/distributions/init.js
index 0bf5b09037..2bb6062097 100644
--- a/tasks/admin/distributions/init.js
+++ b/tasks/admin/distributions/init.js
@@ -12,7 +12,7 @@
 
 */
 
-var
+let
     gulp      = require('gulp'),
 
     // node dependencies
@@ -38,7 +38,7 @@ var
 ;
 
 module.exports = function (callback) {
-    var
+    let
         index = -1,
         total = release.distributions.length,
         timer,
@@ -62,7 +62,7 @@ module.exports = function (callback) {
             return;
         }
 
-        var
+        let
             component          = release.distributions[index],
             lowerCaseComponent = component.toLowerCase(),
             outputDirectory    = path.resolve(release.outputRoot + lowerCaseComponent),
diff --git a/tasks/admin/distributions/update.js b/tasks/admin/distributions/update.js
index f3c92cc6a4..8addaf9aa5 100644
--- a/tasks/admin/distributions/update.js
+++ b/tasks/admin/distributions/update.js
@@ -12,7 +12,7 @@
 
 */
 
-var
+let
     gulp           = require('gulp'),
 
     // node dependencies
@@ -36,7 +36,7 @@ var
 ;
 
 module.exports = function (callback) {
-    var
+    let
         index = -1,
         total = release.distributions.length,
         timer,
@@ -59,7 +59,7 @@ module.exports = function (callback) {
             return;
         }
 
-        var
+        let
             distribution         = release.distributions[index],
             outputDirectory      = path.resolve(path.join(release.outputRoot, distribution.toLowerCase())),
             repoName             = release.distRepoRoot + distribution,
diff --git a/tasks/admin/publish.js b/tasks/admin/publish.js
index fd9e7f41e7..6c24131771 100644
--- a/tasks/admin/publish.js
+++ b/tasks/admin/publish.js
@@ -9,7 +9,7 @@
 
 */
 
-var
+let
     gulp = require('gulp')
 ;
 
diff --git a/tasks/admin/register.js b/tasks/admin/register.js
index 33edb25fbc..ab72d0e6b8 100644
--- a/tasks/admin/register.js
+++ b/tasks/admin/register.js
@@ -8,7 +8,7 @@
   * Registers component with NPM
 */
 
-var
+let
     // node dependencies
     process = require('child_process'),
 
@@ -35,7 +35,7 @@ module.exports = function (callback) {
 
             return;
         }
-        var
+        let
             repo            = repos[index].toLowerCase(),
             outputDirectory = release.outputRoot + repo + '/',
             exec            = process.exec,
diff --git a/tasks/admin/release.js b/tasks/admin/release.js
index 19c2955e08..cf18cd558c 100644
--- a/tasks/admin/release.js
+++ b/tasks/admin/release.js
@@ -10,7 +10,7 @@
 
 */
 
-var
+let
     gulp = require('gulp')
 ;
 
diff --git a/tasks/build.js b/tasks/build.js
index 921739b499..f4211a2b51 100644
--- a/tasks/build.js
+++ b/tasks/build.js
@@ -2,7 +2,7 @@
  *         Build Task
  *******************************/
 
-var
+let
     // dependencies
     gulp     = require('gulp'),
 
diff --git a/tasks/build/assets.js b/tasks/build/assets.js
index e3a9e62c5f..93539ca786 100644
--- a/tasks/build/assets.js
+++ b/tasks/build/assets.js
@@ -2,7 +2,7 @@
  Build Task
  *******************************/
 
-var
+let
     gulp      = require('gulp'),
 
     // gulp dependencies
@@ -42,7 +42,7 @@ function buildAssets(src, config, callback) {
     }
 
     // copy assets
-    var assets         = () => build(src, config);
+    let assets         = () => build(src, config);
     assets.displayName = 'Building Assets';
 
     gulp.series(assets)(callback);
diff --git a/tasks/check-install.js b/tasks/check-install.js
index a916fcd5da..ecda387473 100644
--- a/tasks/check-install.js
+++ b/tasks/check-install.js
@@ -2,7 +2,7 @@
  *        Check Install
  *******************************/
 
-var
+let
     // node dependencies
     gulp    = require('gulp'),
     console = require('better-console'),
diff --git a/tasks/clean.js b/tasks/clean.js
index db417770c3..b92079a7fd 100644
--- a/tasks/clean.js
+++ b/tasks/clean.js
@@ -2,7 +2,7 @@
           Clean Task
 *******************************/
 
-var
+let
     del    = require('del'),
     config = require('./config/user'),
     tasks  = require('./config/tasks')
diff --git a/tasks/collections/README.md b/tasks/collections/README.md
index 53e0c70711..130aa1434b 100644
--- a/tasks/collections/README.md
+++ b/tasks/collections/README.md
@@ -4,11 +4,9 @@ These are collections of tasks that are imported together.
 
 To import them into gulp:
 ```javascript
-var
-  gulp    = require('gulp'),
-  // modified to point to semantic folder
-  install = require('tasks/collections/install')
-;
+const gulp = require('gulp');
+// modified to point to semantic folder
+const install = require('tasks/collections/install');
 gulp = install(gulp);
 
 // tasks are now injected and ready to be used
diff --git a/tasks/collections/admin.js b/tasks/collections/admin.js
index 296196d7a7..ed18ce6819 100644
--- a/tasks/collections/admin.js
+++ b/tasks/collections/admin.js
@@ -14,7 +14,7 @@
  *******************************/
 
 module.exports = function (gulp) {
-    var
+    let
         // less/css distributions
         initComponents      = require('../admin/components/init'),
         createComponents    = require('../admin/components/create'),
diff --git a/tasks/collections/docs.js b/tasks/collections/docs.js
index 934cf2e7f4..4c6439ba30 100644
--- a/tasks/collections/docs.js
+++ b/tasks/collections/docs.js
@@ -7,7 +7,7 @@
   https://github.com/Semantic-Org/Semantic-UI-Docs/
 */
 module.exports = function (gulp) {
-    var
+    let
         // docs tasks
         serveDocs = require('../docs/serve'),
         buildDocs = require('../docs/build')
diff --git a/tasks/collections/install.js b/tasks/collections/install.js
index 74c26a1b18..9995676016 100644
--- a/tasks/collections/install.js
+++ b/tasks/collections/install.js
@@ -7,7 +7,7 @@
   https://github.com/Semantic-Org/Semantic-UI-Docs/
 */
 module.exports = function (gulp) {
-    var
+    let
         // docs tasks
         install      = require('../install'),
         checkInstall = require('../check-install')
diff --git a/tasks/collections/rtl.js b/tasks/collections/rtl.js
index 3e4ab0b6a4..4b6a870dd2 100644
--- a/tasks/collections/rtl.js
+++ b/tasks/collections/rtl.js
@@ -4,7 +4,7 @@
 
 module.exports = function (gulp) {
     // rtl
-    var
+    let
         buildRTL = require('../rtl/build'),
         watchRTL = require('../rtl/watch')
     ;
diff --git a/tasks/collections/various.js b/tasks/collections/various.js
index 5188483cb2..a8df262cc4 100644
--- a/tasks/collections/various.js
+++ b/tasks/collections/various.js
@@ -7,7 +7,7 @@
   https://github.com/Semantic-Org/Semantic-UI-Docs/
 */
 module.exports = function (gulp) {
-    var
+    let
         clean   = require('../clean'),
         version = require('../version')
     ;
diff --git a/tasks/config/admin/github.js b/tasks/config/admin/github.js
index 1568d523f2..20eca32828 100644
--- a/tasks/config/admin/github.js
+++ b/tasks/config/admin/github.js
@@ -5,7 +5,7 @@
   Logs into GitHub using OAuth
 */
 
-var
+let
     fs          = require('fs'),
     path        = require('path'),
     githubAPI   = require('@octokit/rest'),
diff --git a/tasks/config/admin/templates/css-package.js b/tasks/config/admin/templates/css-package.js
index 6dfc6fa177..599f06a7ce 100644
--- a/tasks/config/admin/templates/css-package.js
+++ b/tasks/config/admin/templates/css-package.js
@@ -1,4 +1,4 @@
-var
+let
     where = 'client' // Adds files only to the client
 ;
 
diff --git a/tasks/config/admin/templates/less-package.js b/tasks/config/admin/templates/less-package.js
index 6b064efb2b..35524bcec4 100644
--- a/tasks/config/admin/templates/less-package.js
+++ b/tasks/config/admin/templates/less-package.js
@@ -1,4 +1,4 @@
-var
+let
     where = 'client' // Adds files only to the client
 ;
 
diff --git a/tasks/config/npm/gulpfile.js b/tasks/config/npm/gulpfile.js
index 18b46d26cd..b6b1399c39 100644
--- a/tasks/config/npm/gulpfile.js
+++ b/tasks/config/npm/gulpfile.js
@@ -2,7 +2,7 @@
  *           Set-up
  *******************************/
 
-var
+let
     gulp   = require('gulp'),
 
     // read user config to know what task to load
diff --git a/tasks/config/project/config.js b/tasks/config/project/config.js
index 64ca99cf2a..7d48860955 100644
--- a/tasks/config/project/config.js
+++ b/tasks/config/project/config.js
@@ -2,8 +2,7 @@
             Set-up
 *******************************/
 
-var
-    extend   = require('extend'),
+let
     fs       = require('fs'),
     path     = require('path'),
 
@@ -20,7 +19,7 @@ module.exports = {
         var
             configPath,
             walk = function (directory) {
-                var
+                let
                     nextDirectory = path.resolve(path.join(directory, path.sep, '..')),
                     currentPath   = path.normalize(path.join(directory, file))
                 ;
@@ -50,13 +49,11 @@ module.exports = {
 
     // adds additional derived values to a config object
     addDerivedValues: function (config) {
-        config = config || extend(false, {}, defaults);
-
         /* --------------
             File Paths
         --------------- */
 
-        var
+        let
             configPath = this.getPath(),
             sourcePaths = {},
             outputPaths = {},
@@ -140,8 +137,6 @@ module.exports = {
         config.globs.individuals = individuals.length === 1 ? individuals[0] : (individuals.length > 1)
             ? '{' + individuals.join(',') + '}'
             : undefined;
-
-        return config;
     },
 
 };
diff --git a/tasks/config/project/install.js b/tasks/config/project/install.js
index 6df24b4eff..e1d47bebe6 100644
--- a/tasks/config/project/install.js
+++ b/tasks/config/project/install.js
@@ -2,7 +2,7 @@
             Set-up
 *******************************/
 
-var
+let
     fs             = require('fs'),
     path           = require('path'),
     defaults       = require('../defaults'),
@@ -17,7 +17,7 @@ var
 
 /* Preconditions for install questions */
 
-var when = {
+let when = {
 
     // path
     changeRoot: function (questions) {
@@ -26,7 +26,7 @@ var when = {
 
     // permissions
     changePermissions: function (questions) {
-        return (questions.changePermissions && questions.changePermissions === true);
+        return questions.changePermissions === true;
     },
 
     // install
@@ -65,7 +65,7 @@ var when = {
 
 /* Filters to user input from install questions */
 
-var filter = {
+let filter = {
     removeTrailingSlash: function (path) {
         return path.replace(/(\/$|\\$)+/mg, '');
     },
@@ -84,7 +84,7 @@ module.exports = {
 
     // detect whether there is a semantic.json configuration and that the auto-install option is set to true
     shouldAutoInstall: function () {
-        var
+        let
             config = when.hasConfig()
         ;
 
@@ -96,7 +96,7 @@ module.exports = {
         var
             // returns last matching result (avoid sub-module detection)
             walk = function (directory) {
-                var
+                let
                     pathArray     = directory.split(path.sep),
                     folder        = pathArray[pathArray.length - 1],
                     nextDirectory = path.join(directory, path.sep, '..')
@@ -136,7 +136,7 @@ module.exports = {
         var
             moduleFolders = 0,
             walk = function (directory) {
-                var
+                let
                     pathArray     = directory.split(path.sep),
                     folder        = pathArray[pathArray.length - 2],
                     nextDirectory = path.join(directory, path.sep, '..')
@@ -161,7 +161,7 @@ module.exports = {
     },
 
     createJSON: function (answers) {
-        var
+        let
             json = {
                 paths: {
                     source: {},
diff --git a/tasks/config/project/release.js b/tasks/config/project/release.js
index 60fe6cb8a4..7f5b8fc90b 100644
--- a/tasks/config/project/release.js
+++ b/tasks/config/project/release.js
@@ -2,7 +2,7 @@
          Release Config
 *******************************/
 
-var
+let
     requireDotFile = require('require-dot-file'),
     config,
     npmPackage,
diff --git a/tasks/config/tasks.js b/tasks/config/tasks.js
index 9a93de6eda..fa646469db 100644
--- a/tasks/config/tasks.js
+++ b/tasks/config/tasks.js
@@ -1,15 +1,15 @@
-var
+let
     browserslist = require('browserslist'),
     console = require('better-console'),
     config  = require('./user'),
     release = require('./project/release')
 ;
 
-var defaultBrowsers = browserslist(browserslist.defaults);
-var userBrowsers = browserslist();
-var hasBrowserslistConfig = JSON.stringify(defaultBrowsers) !== JSON.stringify(userBrowsers);
+let defaultBrowsers = browserslist(browserslist.defaults);
+let userBrowsers = browserslist();
+let hasBrowserslistConfig = JSON.stringify(defaultBrowsers) !== JSON.stringify(userBrowsers);
 
-var overrideBrowserslist = hasBrowserslistConfig ? undefined : [
+let overrideBrowserslist = hasBrowserslistConfig ? undefined : [
     'last 2 versions',
     '> 1%',
     'opera 12.1',
@@ -18,7 +18,7 @@ var overrideBrowserslist = hasBrowserslistConfig ? undefined : [
 ];
 
 // Node 12 does not support ??, so a little polyfill
-var nullish = (value, fallback) => {
+let nullish = (value, fallback) => {
     return value !== undefined && value !== null ? value : fallback;
 };
 
@@ -107,7 +107,7 @@ module.exports = {
         plumber: {
             less: {
                 errorHandler: function (error) {
-                    var
+                    let
                         regExp = {
                             variable: /@(\S.*?)\s/,
                             theme: /themes[\/\\]+(.*?)[\/\\].*/,
diff --git a/tasks/config/user.js b/tasks/config/user.js
index 11bd8c8fbb..b355fcc288 100644
--- a/tasks/config/user.js
+++ b/tasks/config/user.js
@@ -2,7 +2,7 @@
              Set-up
 *******************************/
 
-var
+let
     // npm dependencies
     extend          = require('extend'),
     fs              = require('fs'),
diff --git a/tasks/docs/build.js b/tasks/docs/build.js
index 771421aaf5..c313e3129a 100644
--- a/tasks/docs/build.js
+++ b/tasks/docs/build.js
@@ -2,7 +2,8 @@
  Build Docs
  *******************************/
 
-var
+let
+    extend      = require('extend'),
     gulp        = require('gulp'),
 
     // node dependencies
@@ -14,7 +15,7 @@ var
     print       = require('gulp-print').default,
 
     // user config
-    config      = require('../config/docs'),
+    configDocs      = require('../config/docs'),
 
     // install config
     tasks       = require('../config/tasks'),
@@ -35,7 +36,8 @@ var
 
 module.exports = function (callback) {
     // use a different config
-    config = configSetup.addDerivedValues(config);
+    const config = extend(true, {}, configDocs);
+    configSetup.addDerivedValues(config);
 
     // shorthand
     const globs  = config.globs;
diff --git a/tasks/docs/metadata.js b/tasks/docs/metadata.js
index 1c110617eb..882d9ea28e 100644
--- a/tasks/docs/metadata.js
+++ b/tasks/docs/metadata.js
@@ -2,14 +2,14 @@
            Summarize Docs
 *******************************/
 
-var
+let
     // node dependencies
     console      = require('better-console'),
     fs           = require('fs'),
     YAML         = require('yamljs')
 ;
 
-var data = {};
+let data = {};
 
 /**
  * Test for prefix in string.
@@ -22,8 +22,8 @@ function startsWith(str, prefix) {
 }
 
 function inArray(needle, haystack) {
-    var length = haystack.length;
-    for (var i = 0; i < length; i++) {
+    let length = haystack.length;
+    for (let i = 0; i < length; i++) {
         if (haystack[i] == needle) {
             return true;
         }
@@ -68,7 +68,7 @@ function parser(file, callback) {
 
         filename = filename.slice(position + key.length + 1, filename.length);
 
-        var
+        let
             lineCount = lines.length,
             active    = false,
             yaml      = [],
diff --git a/tasks/docs/serve.js b/tasks/docs/serve.js
index ebb30478b8..8fc085019e 100644
--- a/tasks/docs/serve.js
+++ b/tasks/docs/serve.js
@@ -1,7 +1,8 @@
 /*******************************
  Serve Docs
  *******************************/
-var
+let
+    extend      = require('extend'),
     gulp        = require('gulp'),
 
     // node dependencies
@@ -11,7 +12,7 @@ var
     print       = require('gulp-print').default,
 
     // user config
-    config      = require('../config/docs'),
+    configDocs      = require('../config/docs'),
 
     // task config
     tasks       = require('../config/tasks'),
@@ -27,7 +28,8 @@ var
 
 module.exports = function () {
     // use a different config
-    config = configSetup.addDerivedValues(config);
+    const config = extend(true, {}, configDocs);
+    configSetup.addDerivedValues(config);
 
     console.clear();
     console.log('Watching source files for changes');
diff --git a/tasks/install.js b/tasks/install.js
index 45659c7e39..9683cb6c92 100644
--- a/tasks/install.js
+++ b/tasks/install.js
@@ -13,7 +13,7 @@
    * Standard installer runs asking for paths to site files etc
 */
 
-var
+let
     gulp           = require('gulp'),
 
     // node dependencies
@@ -54,7 +54,7 @@ var
 
 // Export install task
 module.exports = function (callback) {
-    var
+    let
         currentConfig = requireDotFile('semantic.json', process.cwd()),
         manager       = install.getPackageManager(),
         rootQuestions = questions.root,
@@ -84,7 +84,7 @@ module.exports = function (callback) {
 
     // run update scripts if semantic.json exists
     if (currentConfig && manager.name === 'NPM') {
-        var
+        let
             updateFolder = path.join(manager.root, currentConfig.base),
             updatePaths  = {
                 config: path.join(manager.root, files.config),
@@ -226,7 +226,7 @@ module.exports = function (callback) {
              Paths
         --------------- */
 
-        var
+        let
             installPaths = {
                 config: files.config,
                 configFolder: folders.config,
@@ -267,7 +267,7 @@ module.exports = function (callback) {
             installFolder = path.join(manager.root, answers.semanticRoot);
 
             // add install folder to all output paths
-            for (var destination in installPaths) {
+            for (let destination in installPaths) {
                 if (installPaths.hasOwnProperty(destination)) {
                     // config goes in project root, rest in install folder
                     installPaths[destination] = (destination == 'config' || destination == 'configFolder')
@@ -334,7 +334,7 @@ module.exports = function (callback) {
         --------------- */
 
         gulp.task('create theme.config', function () {
-            var
+            let
                 // determine path to site theme folder from theme config
                 // force CSS path variable to use forward slashes for paths
                 pathToSite   = path.relative(path.resolve(installPaths.themeConfigFolder), path.resolve(installPaths.site)).replace(/\\/g, '/'),
@@ -369,7 +369,7 @@ module.exports = function (callback) {
         --------------- */
 
         gulp.task('create semantic.json', function () {
-            var
+            let
                 jsonConfig = install.createJSON(answers)
             ;
 
diff --git a/tasks/rtl/build.js b/tasks/rtl/build.js
index a3d1f34baf..d42be80fc8 100644
--- a/tasks/rtl/build.js
+++ b/tasks/rtl/build.js
@@ -2,7 +2,7 @@
  *         Build Task
  *******************************/
 
-var
+let
     gulp = require('gulp')
 ;
 
diff --git a/tasks/rtl/watch.js b/tasks/rtl/watch.js
index 04c82c9384..389ce9a660 100644
--- a/tasks/rtl/watch.js
+++ b/tasks/rtl/watch.js
@@ -2,7 +2,7 @@
  *          Watch Task
  *******************************/
 
-var
+let
     gulp = require('gulp')
 ;
 
diff --git a/tasks/version.js b/tasks/version.js
index 574835c1a4..25f84a7c1c 100644
--- a/tasks/version.js
+++ b/tasks/version.js
@@ -2,7 +2,7 @@
           Version Task
 *******************************/
 
-var
+let
     release = require('./config/project/release')
 ;
 
diff --git a/tasks/watch.js b/tasks/watch.js
index f192c2295d..dd12932358 100644
--- a/tasks/watch.js
+++ b/tasks/watch.js
@@ -2,7 +2,7 @@
  *          Watch Task
  *******************************/
 
-var
+let
     gulp       = require('gulp'),
 
     // node dependencies
diff --git a/test/meteor/assets.js b/test/meteor/assets.js
index 50a13a110c..83583b487c 100644
--- a/test/meteor/assets.js
+++ b/test/meteor/assets.js
@@ -1,4 +1,4 @@
-var assets = [
+let assets = [
     'dist/themes/default/assets/images/flags.png',
 ];
 
diff --git a/test/modules/module.spec.js b/test/modules/module.spec.js
index b917c3f9fb..4b9eee3e6b 100644
--- a/test/modules/module.spec.js
+++ b/test/modules/module.spec.js
@@ -1,5 +1,5 @@
 function moduleTests(ui) {
-    var
+    let
         module    = ui.module,
         element   = ui.element,
         singleton = ui.singleton,
@@ -59,18 +59,18 @@ function moduleTests(ui) {
     -------------------- */
     describe('Module', function () {
         it('allows chaining when no settings returned', function () {
-            var $chain = $modules[module]();
+            let $chain = $modules[module]();
             expect($chain).toExist();
             expect($chain.size()).toBe($modules.size());
         });
 
         it('returns a string when one setting returned', function () {
-            var result = $oneModule[module]('setting', 'name');
+            let result = $oneModule[module]('setting', 'name');
             expect(typeof result).toBe('string');
         });
 
         it('returns an array when multiple settings returned', function () {
-            var result = $modules[module]('setting', 'name');
+            let result = $modules[module]('setting', 'name');
             expect($.isArray(result)).toBeTruthy();
         });
 
@@ -90,7 +90,7 @@ function moduleTests(ui) {
                 name: testValue,
             });
 
-            var retrievedValue = $oneModule[module]('setting', 'name');
+            let retrievedValue = $oneModule[module]('setting', 'name');
             expect(retrievedValue).toBe(testValue);
 
             // reinit
@@ -103,7 +103,7 @@ function moduleTests(ui) {
             $.fn[module].settings.name = testValue;
             $oneModule[module]();
 
-            var retrievedValue = $oneModule[module]('setting', 'name');
+            let retrievedValue = $oneModule[module]('setting', 'name');
             $.fn[module].settings.name = name;
 
             expect(retrievedValue).toBe(testValue);
@@ -114,7 +114,7 @@ function moduleTests(ui) {
                 name: testValue,
             });
 
-            var retrievedValue = $oneModule[module]('setting', 'name');
+            let retrievedValue = $oneModule[module]('setting', 'name');
 
             expect(retrievedValue).toBe(testValue);
         });
@@ -122,7 +122,7 @@ function moduleTests(ui) {
         it('allows settings to be changed during runtime', function () {
             $oneModule[module]();
 
-            var retrievedValue = $oneModule[module]('setting', 'name');
+            let retrievedValue = $oneModule[module]('setting', 'name');
 
             expect(retrievedValue).toBe(name);
         });
@@ -137,8 +137,8 @@ function moduleTests(ui) {
             it('creates settings for all instances', function () {
                 $modules[module]('setting', 'name', testValue);
 
-                var retrievedValue = $oneModule[module]('setting', 'name');
-                var clonedSetting  = $clone[module]('setting', 'name');
+                let retrievedValue = $oneModule[module]('setting', 'name');
+                let clonedSetting  = $clone[module]('setting', 'name');
 
                 expect(retrievedValue).toBe(testValue);
                 expect(clonedSetting).toBe(testValue);
@@ -155,8 +155,8 @@ function moduleTests(ui) {
                 $modules[module]();
                 $oneModule[module]('setting', 'name', testValue);
 
-                var retrievedValue = $oneModule[module]('setting', 'name');
-                var clonedSetting  = $clone[module]('setting', 'name');
+                let retrievedValue = $oneModule[module]('setting', 'name');
+                let clonedSetting  = $clone[module]('setting', 'name');
 
                 expect(retrievedValue).toBe(testValue);
                 expect(clonedSetting).toBe(name);
@@ -169,8 +169,8 @@ function moduleTests(ui) {
                     name: testValue,
                 });
 
-                var retrievedValue = $oneModule[module]('setting', 'name');
-                var clonedSetting  = $clone[module]('setting', 'name');
+                let retrievedValue = $oneModule[module]('setting', 'name');
+                let clonedSetting  = $clone[module]('setting', 'name');
 
                 expect(retrievedValue).toBe(testValue);
                 expect(clonedSetting).toBe(name);