diff --git a/build/gulpfile.editor.js b/build/gulpfile.editor.js
index 938c82f57beab64752fca026b5a6e4c9c6070751..7f52fbff35510fde884ac2484cf42c7c972a1f9e 100644
--- a/build/gulpfile.editor.js
+++ b/build/gulpfile.editor.js
@@ -17,14 +17,14 @@ const compilation = require('./lib/compilation');
 const monacoapi = require('./monaco/api');
 const fs = require('fs');
 
-var root = path.dirname(__dirname);
-var sha1 = util.getVersion(root);
-var semver = require('./monaco/package.json').version;
-var headerVersion = semver + '(' + sha1 + ')';
+let root = path.dirname(__dirname);
+let sha1 = util.getVersion(root);
+let semver = require('./monaco/package.json').version;
+let headerVersion = semver + '(' + sha1 + ')';
 
 // Build
 
-var editorEntryPoints = [
+let editorEntryPoints = [
 	{
 		name: 'vs/editor/editor.main',
 		include: [],
@@ -40,11 +40,11 @@ var editorEntryPoints = [
 	}
 ];
 
-var editorResources = [
+let editorResources = [
 	'out-editor-build/vs/base/browser/ui/codiconLabel/**/*.ttf'
 ];
 
-var BUNDLED_FILE_HEADER = [
+let BUNDLED_FILE_HEADER = [
 	'/*!-----------------------------------------------------------',
 	' * Copyright (c) Microsoft Corporation. All rights reserved.',
 	' * Version: ' + headerVersion,
@@ -263,7 +263,7 @@ const finalEditorResourcesTask = task.define('final-editor-resources', () => {
 		// package.json
 		gulp.src('build/monaco/package.json')
 			.pipe(es.through(function (data) {
-				var json = JSON.parse(data.contents.toString());
+				let json = JSON.parse(data.contents.toString());
 				json.private = false;
 				data.contents = Buffer.from(JSON.stringify(json, null, '  '));
 				this.emit('data', data);
@@ -307,10 +307,10 @@ const finalEditorResourcesTask = task.define('final-editor-resources', () => {
 				return;
 			}
 
-			var relativePathToMap = path.relative(path.join(data.relative), path.join('min-maps', data.relative + '.map'));
+			let relativePathToMap = path.relative(path.join(data.relative), path.join('min-maps', data.relative + '.map'));
 
-			var strContents = data.contents.toString();
-			var newStr = '//# sourceMappingURL=' + relativePathToMap.replace(/\\/g, '/');
+			let strContents = data.contents.toString();
+			let newStr = '//# sourceMappingURL=' + relativePathToMap.replace(/\\/g, '/');
 			strContents = strContents.replace(/\/\/# sourceMappingURL=[^ ]+$/, newStr);
 
 			data.contents = Buffer.from(strContents);
diff --git a/build/gulpfile.reh.js b/build/gulpfile.reh.js
index a956fba979ef6563ac47fe0b355006df9c5cb891..f2ea1bd37010b1eb8a43ce9beaae4a88810f6e2d 100644
--- a/build/gulpfile.reh.js
+++ b/build/gulpfile.reh.js
@@ -118,7 +118,7 @@ function mixinServer(watch) {
 	const packageJSONPath = path.join(path.dirname(__dirname), 'package.json');
 	function exec(cmdLine) {
 		console.log(cmdLine);
-		cp.execSync(cmdLine, { stdio: "inherit" });
+		cp.execSync(cmdLine, { stdio: 'inherit' });
 	}
 	function checkout() {
 		const packageJSON = JSON.parse(fs.readFileSync(packageJSONPath).toString());
diff --git a/build/gulpfile.vscode.js b/build/gulpfile.vscode.js
index bb504fc09e97072a5d712a2143da2cec0855d1d0..4906bfdb1a24ce928c8362de33fb61a50bdfd211 100644
--- a/build/gulpfile.vscode.js
+++ b/build/gulpfile.vscode.js
@@ -121,9 +121,9 @@ gulp.task(minifyVSCodeTask);
  * @return {Object} A map of paths to checksums.
  */
 function computeChecksums(out, filenames) {
-	var result = {};
+	let result = {};
 	filenames.forEach(function (filename) {
-		var fullPath = path.join(process.cwd(), out, filename);
+		let fullPath = path.join(process.cwd(), out, filename);
 		result[filename] = computeChecksum(fullPath);
 	});
 	return result;
@@ -136,9 +136,9 @@ function computeChecksums(out, filenames) {
  * @return {string} The checksum for `filename`.
  */
 function computeChecksum(filename) {
-	var contents = fs.readFileSync(filename);
+	let contents = fs.readFileSync(filename);
 
-	var hash = crypto
+	let hash = crypto
 		.createHash('md5')
 		.update(contents)
 		.digest('base64')
@@ -428,7 +428,7 @@ gulp.task('vscode-translations-pull', function () {
 });
 
 gulp.task('vscode-translations-import', function () {
-	var options = minimist(process.argv.slice(2), {
+	let options = minimist(process.argv.slice(2), {
 		string: 'location',
 		default: {
 			location: '../vscode-translations-import'
diff --git a/build/gulpfile.vscode.linux.js b/build/gulpfile.vscode.linux.js
index 9d3a7caa07e683b571224c8bfcc86665d1c5a98a..51c7002f5b12cf82fbb82b3b9ccceb1bdf283a7f 100644
--- a/build/gulpfile.vscode.linux.js
+++ b/build/gulpfile.vscode.linux.js
@@ -23,7 +23,7 @@ const commit = util.getVersion(root);
 const linuxPackageRevision = Math.floor(new Date().getTime() / 1000);
 
 function getDebPackageArch(arch) {
-	return { x64: 'amd64', arm: 'armhf', arm64: "arm64" }[arch];
+	return { x64: 'amd64', arm: 'armhf', arm64: 'arm64' }[arch];
 }
 
 function prepareDebPackage(arch) {
@@ -117,7 +117,7 @@ function getRpmBuildPath(rpmArch) {
 }
 
 function getRpmPackageArch(arch) {
-	return { x64: 'x86_64', arm: 'armhf', arm64: "arm64" }[arch];
+	return { x64: 'x86_64', arm: 'armhf', arm64: 'arm64' }[arch];
 }
 
 function prepareRpmPackage(arch) {