diff --git a/.eslintrc.json b/.eslintrc.json
index 96060c6b9..c498c3d2a 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -1,7 +1,7 @@
 {
 	"root": true,
 	"extends": [
-		"wikimedia/client-es5",
+		"wikimedia/client",
 		"wikimedia/jquery",
 		"wikimedia/mediawiki"
 	]
diff --git a/FancyCaptcha/resources/ext.confirmEdit.fancyCaptcha.js b/FancyCaptcha/resources/ext.confirmEdit.fancyCaptcha.js
index 03a5ada1c..f46d0c1e7 100644
--- a/FancyCaptcha/resources/ext.confirmEdit.fancyCaptcha.js
+++ b/FancyCaptcha/resources/ext.confirmEdit.fancyCaptcha.js
@@ -1,6 +1,6 @@
 /* eslint-disable no-jquery/no-global-selector */
 $( document ).on( 'click', '.fancycaptcha-reload', function () {
-	var $this = $( this ),
+	const $this = $( this ),
 		$root = $this.closest( '.fancycaptcha-captcha-container' ),
 		$captchaImage = $root.find( '.fancycaptcha-image' );
 
@@ -8,8 +8,8 @@ $( document ).on( 'click', '.fancycaptcha-reload', function () {
 
 	// AJAX request to get captcha index key
 	new mw.Api().post( { action: 'fancycaptchareload' } ).done( function ( data ) {
-		var captchaIndex = data.fancycaptchareload.index,
-			imgSrc;
+		const captchaIndex = data.fancycaptchareload.index;
+		let imgSrc;
 		if ( typeof captchaIndex === 'string' ) {
 			// replace index key with a new one for captcha image
 			imgSrc = $captchaImage.attr( 'src' ).replace( /(wpCaptchaId=)\w+/, '$1' + captchaIndex );
diff --git a/Gruntfile.js b/Gruntfile.js
index fe3c9188a..cdb5b91f3 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -1,8 +1,8 @@
 /* eslint-env node */
 module.exports = function ( grunt ) {
-	var messagesDirs = grunt.file.readJSON( 'extension.json' ).MessagesDirs;
+	const messagesDirs = grunt.file.readJSON( 'extension.json' ).MessagesDirs;
 
-	var subExtensions = [
+	const subExtensions = [
 		'QuestyCaptcha',
 		'ReCaptchaNoCaptcha',
 		'FancyCaptcha',
diff --git a/ReCaptchaNoCaptcha/resources/ve-confirmedit-reCaptchaNoCaptcha/ve.init.mw.NoCaptchaReCaptchaSaveErrorHandler.js b/ReCaptchaNoCaptcha/resources/ve-confirmedit-reCaptchaNoCaptcha/ve.init.mw.NoCaptchaReCaptchaSaveErrorHandler.js
index eda35444d..306177cb2 100644
--- a/ReCaptchaNoCaptcha/resources/ve-confirmedit-reCaptchaNoCaptcha/ve.init.mw.NoCaptchaReCaptchaSaveErrorHandler.js
+++ b/ReCaptchaNoCaptcha/resources/ve-confirmedit-reCaptchaNoCaptcha/ve.init.mw.NoCaptchaReCaptchaSaveErrorHandler.js
@@ -8,8 +8,8 @@ mw.loader.using( 'ext.visualEditor.targetLoader' ).then( function () {
 		ve.init.mw.NoCaptchaReCaptchaSaveErrorHandler.static.name = 'confirmEditNoCaptchaReCaptcha';
 
 		ve.init.mw.NoCaptchaReCaptchaSaveErrorHandler.static.getReadyPromise = function () {
-			var onLoadFn = 'onRecaptchaLoadCallback' + Date.now(),
-				deferred, config, scriptURL, params;
+			const onLoadFn = 'onRecaptchaLoadCallback' + Date.now();
+			let deferred, config, scriptURL, params;
 
 			if ( !this.readyPromise ) {
 				deferred = $.Deferred();
@@ -27,13 +27,13 @@ mw.loader.using( 'ext.visualEditor.targetLoader' ).then( function () {
 		};
 
 		ve.init.mw.NoCaptchaReCaptchaSaveErrorHandler.static.matchFunction = function ( data ) {
-			var captchaData = ve.getProp( data, 'visualeditoredit', 'edit', 'captcha' );
+			const captchaData = ve.getProp( data, 'visualeditoredit', 'edit', 'captcha' );
 
 			return !!( captchaData && captchaData.type === 'recaptchanocaptcha' );
 		};
 
 		ve.init.mw.NoCaptchaReCaptchaSaveErrorHandler.static.process = function ( data, target ) {
-			var self = this,
+			const self = this,
 				config = mw.config.get( 'wgConfirmEditConfig' ),
 				siteKey = config.reCaptchaSiteKey,
 				$container = $( '<div>' );
diff --git a/hCaptcha/resources/ve-confirmedit-hCaptcha/ve.init.mw.HCaptchaSaveErrorHandler.js b/hCaptcha/resources/ve-confirmedit-hCaptcha/ve.init.mw.HCaptchaSaveErrorHandler.js
index b86730742..a2e637a44 100644
--- a/hCaptcha/resources/ve-confirmedit-hCaptcha/ve.init.mw.HCaptchaSaveErrorHandler.js
+++ b/hCaptcha/resources/ve-confirmedit-hCaptcha/ve.init.mw.HCaptchaSaveErrorHandler.js
@@ -7,8 +7,8 @@ mw.loader.using( 'ext.visualEditor.targetLoader' ).then( function () {
 		ve.init.mw.HCaptchaSaveErrorHandler.static.name = 'confirmEditHCaptcha';
 
 		ve.init.mw.HCaptchaSaveErrorHandler.static.getReadyPromise = function () {
-			var onLoadFn = 'onHcaptchaLoadCallback' + Date.now(),
-				deferred, scriptURL, params;
+			const onLoadFn = 'onHcaptchaLoadCallback' + Date.now();
+			let deferred, scriptURL, params;
 
 			if ( !this.readyPromise ) {
 				deferred = $.Deferred();
@@ -25,13 +25,13 @@ mw.loader.using( 'ext.visualEditor.targetLoader' ).then( function () {
 		};
 
 		ve.init.mw.HCaptchaSaveErrorHandler.static.matchFunction = function ( data ) {
-			var captchaData = ve.getProp( data, 'visualeditoredit', 'edit', 'captcha' );
+			const captchaData = ve.getProp( data, 'visualeditoredit', 'edit', 'captcha' );
 
 			return !!( captchaData && captchaData.type === 'hcaptcha' );
 		};
 
 		ve.init.mw.HCaptchaSaveErrorHandler.static.process = function ( data, target ) {
-			var self = this,
+			const self = this,
 				siteKey = require( './config.json' ).hCaptchaSiteKey,
 				$container = $( '<div>' );
 
diff --git a/resources/libs/ext.confirmEdit.CaptchaInputWidget.js b/resources/libs/ext.confirmEdit.CaptchaInputWidget.js
index 5b336a8fd..410f036a2 100644
--- a/resources/libs/ext.confirmEdit.CaptchaInputWidget.js
+++ b/resources/libs/ext.confirmEdit.CaptchaInputWidget.js
@@ -38,14 +38,13 @@ OO.inheritClass( mw.libs.confirmEdit.CaptchaInputWidget, OO.ui.TextInputWidget )
 /* Methods */
 
 mw.libs.confirmEdit.CaptchaInputWidget.prototype.makeCaptchaInterface = function ( captchaData ) {
-	var $captchaImg, msg, question,
-		$captchaDiv, $captchaParagraph;
+	let $captchaImg, msg, question;
 
-	$captchaParagraph = $( '<div>' ).append(
+	const $captchaParagraph = $( '<div>' ).append(
 		$( '<strong>' ).text( mw.msg( 'captcha-label' ) ),
 		document.createTextNode( mw.msg( 'colon-separator' ) )
 	);
-	$captchaDiv = $( '<div>' ).append( $captchaParagraph );
+	const $captchaDiv = $( '<div>' ).append( $captchaParagraph );
 
 	if ( captchaData.url ) {
 		// FancyCaptcha
diff --git a/resources/ve-confirmedit/ve.init.mw.CaptchaSaveErrorHandler.js b/resources/ve-confirmedit/ve.init.mw.CaptchaSaveErrorHandler.js
index a87f373ad..63bc83d0e 100644
--- a/resources/ve-confirmedit/ve.init.mw.CaptchaSaveErrorHandler.js
+++ b/resources/ve-confirmedit/ve.init.mw.CaptchaSaveErrorHandler.js
@@ -15,7 +15,7 @@ mw.loader.using( 'ext.visualEditor.targetLoader' ).then( function () {
 		ve.init.mw.CaptchaSaveErrorHandler.static.name = 'confirmEditCaptchas';
 
 		ve.init.mw.CaptchaSaveErrorHandler.static.matchFunction = function ( data ) {
-			var captchaData = ve.getProp( data, 'visualeditoredit', 'edit', 'captcha' );
+			const captchaData = ve.getProp( data, 'visualeditoredit', 'edit', 'captcha' );
 
 			return !!( captchaData && (
 				captchaData.url ||
@@ -26,7 +26,10 @@ mw.loader.using( 'ext.visualEditor.targetLoader' ).then( function () {
 		};
 
 		ve.init.mw.CaptchaSaveErrorHandler.static.process = function ( data, target ) {
-			var captchaInput;
+			const captchaInput = new mw.libs.confirmEdit.CaptchaInputWidget(
+				ve.getProp( data, 'visualeditoredit', 'edit', 'captcha' )
+			);
+			ve.targetLinksToNewWindow( captchaInput.$element[ 0 ] );
 
 			function onCaptchaLoad() {
 				target.saveDialog.updateSize();
@@ -34,11 +37,6 @@ mw.loader.using( 'ext.visualEditor.targetLoader' ).then( function () {
 				captchaInput.scrollElementIntoView();
 			}
 
-			captchaInput = new mw.libs.confirmEdit.CaptchaInputWidget(
-				ve.getProp( data, 'visualeditoredit', 'edit', 'captcha' )
-			);
-			ve.targetLinksToNewWindow( captchaInput.$element[ 0 ] );
-
 			captchaInput.on( 'load', onCaptchaLoad );
 			// Save when pressing 'Enter' in captcha field as it is single line.
 			captchaInput.on( 'enter', function () {