diff --git a/packages/rocketchat-custom-sounds/admin/adminSounds.js b/packages/rocketchat-custom-sounds/admin/adminSounds.js
index 15b724d82e9..627eadce9ac 100644
--- a/packages/rocketchat-custom-sounds/admin/adminSounds.js
+++ b/packages/rocketchat-custom-sounds/admin/adminSounds.js
@@ -33,7 +33,7 @@ Template.adminSounds.helpers({
 });
 
 Template.adminSounds.onCreated(function() {
-	let instance = this;
+	const instance = this;
 	this.limit = new ReactiveVar(50);
 	this.filter = new ReactiveVar('');
 	this.ready = new ReactiveVar(false);
@@ -61,22 +61,22 @@ Template.adminSounds.onCreated(function() {
 	});
 
 	this.autorun(function() {
-		let limit = (isSetNotNull(() => instance.limit))? instance.limit.get() : 0;
-		let subscription = instance.subscribe('customSounds', '', limit);
+		const limit = (isSetNotNull(() => instance.limit))? instance.limit.get() : 0;
+		const subscription = instance.subscribe('customSounds', '', limit);
 		instance.ready.set(subscription.ready());
 	});
 
 	this.customsounds = function() {
-		let filter = (isSetNotNull(() => instance.filter))? _.trim(instance.filter.get()) : '';
+		const filter = (isSetNotNull(() => instance.filter))? _.trim(instance.filter.get()) : '';
 
 		let query = {};
 
 		if (filter) {
-			let filterReg = new RegExp(s.escapeRegExp(filter), 'i');
+			const filterReg = new RegExp(s.escapeRegExp(filter), 'i');
 			query = { name: filterReg };
 		}
 
-		let limit = (isSetNotNull(() => instance.limit))? instance.limit.get() : 0;
+		const limit = (isSetNotNull(() => instance.limit))? instance.limit.get() : 0;
 
 		return RocketChat.models.CustomSounds.find(query, { limit: limit, sort: { name: 1 }}).fetch();
 	};
diff --git a/packages/rocketchat-custom-sounds/admin/soundEdit.js b/packages/rocketchat-custom-sounds/admin/soundEdit.js
index 9a7ee93d5fa..53c371306ad 100644
--- a/packages/rocketchat-custom-sounds/admin/soundEdit.js
+++ b/packages/rocketchat-custom-sounds/admin/soundEdit.js
@@ -25,7 +25,7 @@ Template.soundEdit.events({
 	},
 
 	['change input[type=file]'](ev) {
-		let e = (isSetNotNull(() => ev.originalEvent)) ? ev.originalEvent : ev;
+		const e = (isSetNotNull(() => ev.originalEvent)) ? ev.originalEvent : ev;
 		let files = e.target.files;
 		if (!isSetNotNull(() => e.target.files) || files.length === 0) {
 			if (isSetNotNull(() => e.dataTransfer.files)) {
@@ -36,7 +36,7 @@ Template.soundEdit.events({
 		}
 
 		//using let x of y here seems to have incompatibility with some phones
-		for (let file in files) {
+		for (const file in files) {
 			if (files.hasOwnProperty(file)) {
 				Template.instance().soundFile = files[file];
 			}
@@ -61,7 +61,7 @@ Template.soundEdit.onCreated(function() {
 	};
 
 	this.getSoundData = () => {
-		let soundData = {};
+		const soundData = {};
 		if (isSetNotNull(() => this.sound)) {
 			soundData._id = this.sound._id;
 			soundData.previousName = this.sound.name;
@@ -74,9 +74,9 @@ Template.soundEdit.onCreated(function() {
 	};
 
 	this.validate = () => {
-		let soundData = this.getSoundData();
+		const soundData = this.getSoundData();
 
-		let errors = [];
+		const errors = [];
 		if (!soundData.name) {
 			errors.push('Name');
 		}
@@ -87,7 +87,7 @@ Template.soundEdit.onCreated(function() {
 			}
 		}
 
-		for (let error of errors) {
+		for (const error of errors) {
 			toastr.error(TAPi18n.__('error-the-field-is-required', { field: TAPi18n.__(error) }));
 		}
 
@@ -103,7 +103,7 @@ Template.soundEdit.onCreated(function() {
 
 	this.save = (form) => {
 		if (this.validate()) {
-			let soundData = this.getSoundData();
+			const soundData = this.getSoundData();
 
 			if (this.soundFile) {
 				soundData.newFile = true;
@@ -119,7 +119,7 @@ Template.soundEdit.onCreated(function() {
 					if (this.soundFile) {
 						toastr.info(TAPi18n.__('Uploading_file'));
 
-						let reader = new FileReader();
+						const reader = new FileReader();
 						reader.readAsBinaryString(this.soundFile);
 						reader.onloadend = () => {
 							Meteor.call('uploadCustomSound', reader.result, this.soundFile.type, soundData, (uploadError/*, data*/) => {
diff --git a/packages/rocketchat-custom-sounds/admin/soundInfo.js b/packages/rocketchat-custom-sounds/admin/soundInfo.js
index f0f28e42892..fd1f45e802e 100644
--- a/packages/rocketchat-custom-sounds/admin/soundInfo.js
+++ b/packages/rocketchat-custom-sounds/admin/soundInfo.js
@@ -1,7 +1,7 @@
 /* globals isSetNotNull */
 Template.soundInfo.helpers({
 	name() {
-		let sound = Template.instance().sound.get();
+		const sound = Template.instance().sound.get();
 		return sound.name;
 	},
 
@@ -14,14 +14,14 @@ Template.soundInfo.helpers({
 	},
 
 	soundToEdit() {
-		let instance = Template.instance();
+		const instance = Template.instance();
 		return {
 			sound: instance.sound.get(),
 			back(name) {
 				instance.editingSound.set();
 
 				if (isSetNotNull(() => name)) {
-					let sound = instance.sound.get();
+					const sound = instance.sound.get();
 					if (isSetNotNull(() => sound.name) && sound.name !== name) {
 						return instance.loadedName.set(name);
 					}
@@ -35,9 +35,9 @@ Template.soundInfo.events({
 	['click .delete'](e, instance) {
 		e.stopPropagation();
 		e.preventDefault();
-		let sound = instance.sound.get();
+		const sound = instance.sound.get();
 		if (isSetNotNull(() => sound)) {
-			let _id = sound._id;
+			const _id = sound._id;
 			swal({
 				title: t('Are_you_sure'),
 				text: t('Custom_Sound_Delete_Warning'),
@@ -88,15 +88,15 @@ Template.soundInfo.onCreated(function() {
 	this.loadedName = new ReactiveVar();
 
 	this.autorun(() => {
-		let data = Template.currentData();
+		const data = Template.currentData();
 		if (isSetNotNull(() => data.clear)) {
 			this.clear = data.clear;
 		}
 	});
 
 	this.autorun(() => {
-		let data = Template.currentData();
-		let sound = this.sound.get();
+		const data = Template.currentData();
+		const sound = this.sound.get();
 		if (isSetNotNull(() => sound.name)) {
 			this.loadedName.set(sound.name);
 		} else if (isSetNotNull(() => data.name)) {
@@ -105,7 +105,7 @@ Template.soundInfo.onCreated(function() {
 	});
 
 	this.autorun(() => {
-		let data = Template.currentData();
+		const data = Template.currentData();
 		this.sound.set(data);
 	});
 });
diff --git a/packages/rocketchat-custom-sounds/client/lib/CustomSounds.js b/packages/rocketchat-custom-sounds/client/lib/CustomSounds.js
index 540fcbfe6f7..b977cd08f70 100644
--- a/packages/rocketchat-custom-sounds/client/lib/CustomSounds.js
+++ b/packages/rocketchat-custom-sounds/client/lib/CustomSounds.js
@@ -43,7 +43,7 @@ class CustomSounds {
 	}
 
 	getURL(sound) {
-		let path = (Meteor.isCordova) ? Meteor.absoluteUrl().replace(/\/$/, '') : __meteor_runtime_config__.ROOT_URL_PATH_PREFIX || '';
+		const path = (Meteor.isCordova) ? Meteor.absoluteUrl().replace(/\/$/, '') : __meteor_runtime_config__.ROOT_URL_PATH_PREFIX || '';
 		return `${path}/custom-sounds/${sound._id}.${sound.extension}?_dc=${sound.random || 0}`;
 	}
 
@@ -57,7 +57,7 @@ RocketChat.CustomSounds = new CustomSounds;
 
 Meteor.startup(() =>
 	Meteor.call('listCustomSounds', (error, result) => {
-		for (let sound of result) {
+		for (const sound of result) {
 			RocketChat.CustomSounds.add(sound);
 		}
 	})
diff --git a/packages/rocketchat-custom-sounds/server/methods/insertOrUpdateSound.js b/packages/rocketchat-custom-sounds/server/methods/insertOrUpdateSound.js
index 845bda2cec7..c0dc2b72009 100644
--- a/packages/rocketchat-custom-sounds/server/methods/insertOrUpdateSound.js
+++ b/packages/rocketchat-custom-sounds/server/methods/insertOrUpdateSound.js
@@ -13,7 +13,7 @@ Meteor.methods({
 
 		//allow all characters except colon, whitespace, comma, >, <, &, ", ', /, \, (, )
 		//more practical than allowing specific sets of characters; also allows foreign languages
-		let nameValidation = /[\s,:><&"'\/\\\(\)]/;
+		const nameValidation = /[\s,:><&"'\/\\\(\)]/;
 
 		//silently strip colon; this allows for uploading :soundname: as soundname
 		soundData.name = soundData.name.replace(/:/g, '');
@@ -36,12 +36,12 @@ Meteor.methods({
 
 		if (!soundData._id) {
 			//insert sound
-			let createSound = {
+			const createSound = {
 				name: soundData.name,
 				extension: soundData.extension
 			};
 
-			let _id = RocketChat.models.CustomSounds.create(createSound);
+			const _id = RocketChat.models.CustomSounds.create(createSound);
 			createSound._id = _id;
 
 			return _id;
diff --git a/packages/rocketchat-custom-sounds/server/methods/uploadCustomSound.js b/packages/rocketchat-custom-sounds/server/methods/uploadCustomSound.js
index 9929871559a..9dabf715edc 100644
--- a/packages/rocketchat-custom-sounds/server/methods/uploadCustomSound.js
+++ b/packages/rocketchat-custom-sounds/server/methods/uploadCustomSound.js
@@ -5,11 +5,11 @@ Meteor.methods({
 			throw new Meteor.Error('not_authorized');
 		}
 
-		let file = new Buffer(binaryContent, 'binary');
+		const file = new Buffer(binaryContent, 'binary');
 
-		let rs = RocketChatFile.bufferToStream(file);
+		const rs = RocketChatFile.bufferToStream(file);
 		RocketChatFileCustomSoundsInstance.deleteFile(`${soundData._id}.${soundData.extension}`);
-		let ws = RocketChatFileCustomSoundsInstance.createWriteStream(`${soundData._id}.${soundData.extension}`, contentType);
+		const ws = RocketChatFileCustomSoundsInstance.createWriteStream(`${soundData._id}.${soundData.extension}`, contentType);
 		ws.on('end', Meteor.bindEnvironment(() =>
 			Meteor.setTimeout(() => RocketChat.Notifications.notifyAll('updateCustomSound', {soundData})
 			, 500)
diff --git a/packages/rocketchat-custom-sounds/server/models/CustomSounds.js b/packages/rocketchat-custom-sounds/server/models/CustomSounds.js
index 45f742ce5ac..25e7bf27b4b 100644
--- a/packages/rocketchat-custom-sounds/server/models/CustomSounds.js
+++ b/packages/rocketchat-custom-sounds/server/models/CustomSounds.js
@@ -12,7 +12,7 @@ class CustomSounds extends RocketChat.models._Base {
 
 	//find
 	findByName(name, options) {
-		let query = {
+		const query = {
 			name
 		};
 
@@ -20,7 +20,7 @@ class CustomSounds extends RocketChat.models._Base {
 	}
 
 	findByNameExceptID(name, except, options) {
-		let query = {
+		const query = {
 			_id: { $nin: [ except ] },
 			name
 		};
@@ -30,7 +30,7 @@ class CustomSounds extends RocketChat.models._Base {
 
 	//update
 	setName(_id, name) {
-		let update = {
+		const update = {
 			$set: {
 				name
 			}
diff --git a/packages/rocketchat-custom-sounds/server/publications/customSounds.js b/packages/rocketchat-custom-sounds/server/publications/customSounds.js
index 03032018d73..1ecefc930c7 100644
--- a/packages/rocketchat-custom-sounds/server/publications/customSounds.js
+++ b/packages/rocketchat-custom-sounds/server/publications/customSounds.js
@@ -3,21 +3,21 @@ Meteor.publish('customSounds', function(filter, limit) {
 		return this.ready();
 	}
 
-	let fields = {
+	const fields = {
 		name: 1,
 		extension: 1
 	};
 
 	filter = s.trim(filter);
 
-	let options = {
+	const options = {
 		fields,
 		limit,
 		sort: { name: 1 }
 	};
 
 	if (filter) {
-		let filterReg = new RegExp(s.escapeRegExp(filter), 'i');
+		const filterReg = new RegExp(s.escapeRegExp(filter), 'i');
 		return RocketChat.models.CustomSounds.findByName(filterReg, options);
 	}
 
diff --git a/packages/rocketchat-custom-sounds/server/startup/custom-sounds.js b/packages/rocketchat-custom-sounds/server/startup/custom-sounds.js
index 0f8c10a5240..e9141956668 100644
--- a/packages/rocketchat-custom-sounds/server/startup/custom-sounds.js
+++ b/packages/rocketchat-custom-sounds/server/startup/custom-sounds.js
@@ -6,7 +6,7 @@ Meteor.startup(function() {
 		storeType = RocketChat.settings.get('CustomSounds_Storage_Type');
 	}
 
-	let RocketChatStore = RocketChatFile[storeType];
+	const RocketChatStore = RocketChatFile[storeType];
 
 	if (!isSetNotNull(() => RocketChatStore)) {
 		throw new Error(`Invalid RocketChatStore type [${storeType}]`);
@@ -29,7 +29,7 @@ Meteor.startup(function() {
 	self = this;
 
 	return WebApp.connectHandlers.use('/custom-sounds/', Meteor.bindEnvironment(function(req, res/*, next*/) {
-		let params =
+		const params =
 			{ sound: decodeURIComponent(req.url.replace(/^\//, '').replace(/\?.*$/, '')) };
 
 		if (_.isEmpty(params.sound)) {
@@ -39,7 +39,7 @@ Meteor.startup(function() {
 			return;
 		}
 
-		let file = RocketChatFileCustomSoundsInstance.getFileWithReadStream(params.sound);
+		const file = RocketChatFileCustomSoundsInstance.getFileWithReadStream(params.sound);
 		if (!file) {
 			return;
 		}
@@ -51,7 +51,7 @@ Meteor.startup(function() {
 			fileUploadDate = file.uploadDate.toUTCString();
 		}
 
-		let reqModifiedHeader = req.headers['if-modified-since'];
+		const reqModifiedHeader = req.headers['if-modified-since'];
 		if (isSetNotNull(() => reqModifiedHeader)) {
 			if (reqModifiedHeader === fileUploadDate) {
 				res.setHeader('Last-Modified', reqModifiedHeader);
diff --git a/packages/rocketchat-push-notifications/client/views/pushNotificationsFlexTab.js b/packages/rocketchat-push-notifications/client/views/pushNotificationsFlexTab.js
index 2b4f7c0403b..e4b5c94d2d4 100644
--- a/packages/rocketchat-push-notifications/client/views/pushNotificationsFlexTab.js
+++ b/packages/rocketchat-push-notifications/client/views/pushNotificationsFlexTab.js
@@ -231,14 +231,14 @@ Template.pushNotificationsFlexTab.events({
 		e.preventDefault();
 		let audio = $(e.currentTarget).data('play');
 		if (audio && audio !== 'none') {
-			let $audio = $('audio#' + audio);
+			const $audio = $('audio#' + audio);
 			if ($audio && $audio[0] && $audio[0].play) {
 				$audio[0].play();
 			}
 		} else {
 			audio = Meteor.user() && Meteor.user().settings && Meteor.user().settings.preferences && Meteor.user().settings.preferences.newMessageNotification || 'chime';
 			if (audio && audio !== 'none') {
-				let $audio = $('audio#' + audio);
+				const $audio = $('audio#' + audio);
 				if ($audio && $audio[0] && $audio[0].play) {
 					$audio[0].play();
 				}
@@ -248,9 +248,9 @@ Template.pushNotificationsFlexTab.events({
 
 	'change select[name=audioNotification]'(e) {
 		e.preventDefault();
-		let audio = $(e.currentTarget).val();
+		const audio = $(e.currentTarget).val();
 		if (audio && audio !== 'none') {
-			let $audio = $('audio#' + audio);
+			const $audio = $('audio#' + audio);
 			if ($audio && $audio[0] && $audio[0].play) {
 				$audio[0].play();
 			}
diff --git a/server/publications/subscription.js b/server/publications/subscription.js
index c7955bd7fbe..1018e7d1e76 100644
--- a/server/publications/subscription.js
+++ b/server/publications/subscription.js
@@ -12,7 +12,7 @@ const fields = {
 	roles: 1,
 	unread: 1,
 	archived: 1,
-	audioNotification: 1
+	audioNotification: 1,
 	desktopNotifications: 1,
 	desktopNotificationDuration: 1,
 	mobilePushNotifications: 1,