diff --git a/binaries/data/mods/public/gui/credits/credits.js b/binaries/data/mods/public/gui/credits/credits.js
index aa5541d9c2..a85091194b 100644
--- a/binaries/data/mods/public/gui/credits/credits.js
+++ b/binaries/data/mods/public/gui/credits/credits.js
@@ -32,9 +32,9 @@ var g_TabButtonDist = 5;
 function init()
 {
 	// Load credits list from the disk and parse them
-	for (let category of g_OrderTabNames)
+	for (const category of g_OrderTabNames)
 	{
-		let json = Engine.ReadJSONFile("gui/credits/texts/" + category + ".json");
+		const json = Engine.ReadJSONFile("gui/credits/texts/" + category + ".json");
 		if (!json || !json.Content)
 		{
 			if (category == "translators")
@@ -70,7 +70,7 @@ function parseHelper(list)
 {
 	let result = "";
 
-	for (let object of list)
+	for (const object of list)
 	{
 		if (object.LangName)
 			result += setStringTags(object.LangName + "\n", { "font": "sans-bold-stroke-14" });
@@ -83,7 +83,7 @@ function parseHelper(list)
 
 		if (object.List)
 		{
-			for (let element of object.List)
+			for (const element of object.List)
 			{
 				let credit;
 				if (element.nick && element.name)
diff --git a/binaries/data/mods/public/gui/gamesetup_mp/gamesetup_mp.js b/binaries/data/mods/public/gui/gamesetup_mp/gamesetup_mp.js
index 694fca21a3..a442d24abf 100644
--- a/binaries/data/mods/public/gui/gamesetup_mp/gamesetup_mp.js
+++ b/binaries/data/mods/public/gui/gamesetup_mp/gamesetup_mp.js
@@ -51,7 +51,7 @@ async function init(attribs)
 	}
 	case "host":
 	{
-		let hasXmppClient = Engine.HasXmppClient();
+		const hasXmppClient = Engine.HasXmppClient();
 		Engine.GetGUIObjectByName("hostPasswordWrapper").hidden = !hasXmppClient;
 		if (hasXmppClient)
 		{
@@ -130,9 +130,9 @@ function confirmSetup(loadSavedGame)
 {
 	if (!Engine.GetGUIObjectByName("pageJoin").hidden)
 	{
-		let joinPlayerName = Engine.GetGUIObjectByName("joinPlayerName").caption;
-		let joinServer = Engine.GetGUIObjectByName("joinServer").caption;
-		let joinPort = Engine.GetGUIObjectByName("joinPort").caption;
+		const joinPlayerName = Engine.GetGUIObjectByName("joinPlayerName").caption;
+		const joinServer = Engine.GetGUIObjectByName("joinServer").caption;
+		const joinPort = Engine.GetGUIObjectByName("joinPort").caption;
 
 		if (startJoin(joinPlayerName, joinServer, getValidPort(joinPort)))
 		{
@@ -144,14 +144,14 @@ function confirmSetup(loadSavedGame)
 
 	if (!Engine.GetGUIObjectByName("pageHost").hidden)
 	{
-		let hostServerName = Engine.GetGUIObjectByName("hostServerName").caption;
+		const hostServerName = Engine.GetGUIObjectByName("hostServerName").caption;
 		if (!hostServerName)
 		{
 			Engine.GetGUIObjectByName("hostFeedback").caption = translate("Please enter a valid server name.");
 			return false;
 		}
 
-		let hostPort = Engine.GetGUIObjectByName("hostPort").caption;
+		const hostPort = Engine.GetGUIObjectByName("hostPort").caption;
 		if (getValidPort(hostPort) != +hostPort)
 		{
 			Engine.GetGUIObjectByName("hostFeedback").caption = sprintf(
@@ -162,8 +162,8 @@ function confirmSetup(loadSavedGame)
 			return false;
 		}
 
-		let hostPlayerName = Engine.GetGUIObjectByName("hostPlayerName").caption;
-		let hostPassword = Engine.GetGUIObjectByName("hostPassword").caption;
+		const hostPlayerName = Engine.GetGUIObjectByName("hostPlayerName").caption;
+		const hostPassword = Engine.GetGUIObjectByName("hostPassword").caption;
 		if (startHost(hostPlayerName, hostServerName, getValidPort(hostPort), hostPassword,
 			loadSavedGame))
 		{
@@ -367,23 +367,23 @@ async function handleAuthenticated(message, loadSavedGame)
 
 function switchSetupPage(newPage)
 {
-	let multiplayerPages = Engine.GetGUIObjectByName("multiplayerPages");
-	for (let page of multiplayerPages.children)
+	const multiplayerPages = Engine.GetGUIObjectByName("multiplayerPages");
+	for (const page of multiplayerPages.children)
 		if (page.name.startsWith("page"))
 			page.hidden = true;
 
 	if (newPage == "pageJoin" || newPage == "pageHost")
 	{
-		let pageSize = multiplayerPages.size;
-		let halfHeight = newPage == "pageJoin" ? 145 : Engine.HasXmppClient() ? 140 : 125;
+		const pageSize = multiplayerPages.size;
+		const halfHeight = newPage == "pageJoin" ? 145 : Engine.HasXmppClient() ? 140 : 125;
 		pageSize.top = -halfHeight;
 		pageSize.bottom = halfHeight;
 		multiplayerPages.size = pageSize;
 	}
 	else if (newPage == "pagePassword")
 	{
-		let pageSize = multiplayerPages.size;
-		let halfHeight = 60;
+		const pageSize = multiplayerPages.size;
+		const halfHeight = 60;
 		pageSize.top = -halfHeight;
 		pageSize.bottom = halfHeight;
 		multiplayerPages.size = pageSize;
@@ -405,7 +405,7 @@ function startHost(playername, servername, port, password, loadSavedGame)
 	Engine.ConfigDB_CreateValue("user", "multiplayerhosting.port", port);
 	Engine.ConfigDB_SaveChanges("user");
 
-	let hostFeedback = Engine.GetGUIObjectByName("hostFeedback");
+	const hostFeedback = Engine.GetGUIObjectByName("hostFeedback");
 
 	// Disallow identically named games in the multiplayer lobby
 	if (Engine.HasXmppClient() &&
diff --git a/binaries/data/mods/public/gui/hotkeys/HotkeyMetadata.js b/binaries/data/mods/public/gui/hotkeys/HotkeyMetadata.js
index 33754f8906..6d49529221 100644
--- a/binaries/data/mods/public/gui/hotkeys/HotkeyMetadata.js
+++ b/binaries/data/mods/public/gui/hotkeys/HotkeyMetadata.js
@@ -14,30 +14,30 @@ class HotkeyMetadata
 
 	parseSpec()
 	{
-		let files = this.getFiles();
+		const files = this.getFiles();
 		let hotkey_i = 0;
-		let categories = {
+		const categories = {
 			[this.DEFAULT_CATEGORY]: {
 				"name": translate(this.DefaultCategoryString),
 				"desc": translate(this.DefaultCategoryString),
 			}
 		};
-		for (let file of files)
+		for (const file of files)
 		{
-			let data = Engine.ReadJSONFile(file);
+			const data = Engine.ReadJSONFile(file);
 			if (data.categories)
-				for (let cat in data.categories)
+				for (const cat in data.categories)
 					categories[cat] = data.categories[cat];
 			if (data.hotkeys)
-				for (let hotkey in data.hotkeys)
+				for (const hotkey in data.hotkeys)
 				{
 					this.hotkeys[hotkey] = data.hotkeys[hotkey];
 					this.hotkeys[hotkey].order = hotkey_i++;
 					this.hotkeys[hotkey].categories = data.hotkeys[hotkey].categories || [this.DEFAULT_CATEGORY];
 				}
 			if (data.mapped_hotkeys)
-				for (let cat in data.mapped_hotkeys)
-					for (let hotkey in data.mapped_hotkeys[cat])
+				for (const cat in data.mapped_hotkeys)
+					for (const hotkey in data.mapped_hotkeys[cat])
 					{
 						if (data.mapped_hotkeys[cat][hotkey].categories)
 							warn("Categories will be overwritten for mapped hotkey " + hotkey);
@@ -48,14 +48,14 @@ class HotkeyMetadata
 		}
 		// Sort categories (JS objects are (in this case) sorted by insertion order).
 		this.categories = {};
-		let keys = Object.keys(categories).sort((a, b) => {
+		const keys = Object.keys(categories).sort((a, b) => {
 			if (a === this.DEFAULT_CATEGORY || b === this.DEFAULT_CATEGORY)
 				return a === this.DEFAULT_CATEGORY ? 1 : -1;
 			if (categories[a].order === undefined || categories[b].order === undefined)
 				return categories[a].order === undefined ? -1 : 1; // Likely to keep alphabetical order.
 			return categories[a].order - categories[b].order;
 		});
-		for (let key of keys)
+		for (const key of keys)
 			this.categories[key] = categories[key];
 		// TODO: validate that categories exist.
 	}
diff --git a/binaries/data/mods/public/gui/hotkeys/HotkeyPicker.js b/binaries/data/mods/public/gui/hotkeys/HotkeyPicker.js
index ceb686c61d..4a36fdc28c 100644
--- a/binaries/data/mods/public/gui/hotkeys/HotkeyPicker.js
+++ b/binaries/data/mods/public/gui/hotkeys/HotkeyPicker.js
@@ -32,7 +32,7 @@ class HotkeyPicker
 			// This is a bit "using a bazooka to kill a fly"
 			Engine.ConfigDB_RemoveValueAndSave("user", "hotkey." + this.name);
 			Engine.ReloadHotkeys();
-			let data = Engine.GetHotkeyMap();
+			const data = Engine.GetHotkeyMap();
 			this.combinations = data[this.name];
 			this.setupCombinations();
 			this.render();
@@ -49,7 +49,7 @@ class HotkeyPicker
 	{
 		for (let i = 0; i < 4; ++i)
 		{
-			let s = Engine.GetGUIObjectByName("combination[" + i + "]").size;
+			const s = Engine.GetGUIObjectByName("combination[" + i + "]").size;
 			s.top = +i * 60 + 120;
 			s.bottom = +i * 60 + 150;
 			Engine.GetGUIObjectByName("combination[" + i + "]").size = s;
@@ -58,9 +58,9 @@ class HotkeyPicker
 			if (i == this.combinations.length)
 				this.combinations.push([]);
 
-			let input = Engine.GetGUIObjectByName("combMapping[" + i + "]");
+			const input = Engine.GetGUIObjectByName("combMapping[" + i + "]");
 
-			let picker = Engine.GetGUIObjectByName("picker[" + i + "]");
+			const picker = Engine.GetGUIObjectByName("picker[" + i + "]");
 			Engine.GetGUIObjectByName("combMappingBtn[" + i + "]").onPress = () => {
 				this.enteringInput = i;
 				picker.focus();
@@ -99,7 +99,7 @@ class HotkeyPicker
 	{
 		for (let i = 0; i < 4; ++i)
 		{
-			let input = Engine.GetGUIObjectByName("combMapping[" + i + "]");
+			const input = Engine.GetGUIObjectByName("combMapping[" + i + "]");
 			if (i == this.enteringInput)
 				input.caption = translate("Enter new Hotkey, hold to register.");
 			else
@@ -108,7 +108,7 @@ class HotkeyPicker
 
 			Engine.GetGUIObjectByName("deleteComb[" + i + "]").hidden = !this.combinations[i].length;
 
-			let conflicts = (Engine.GetConflicts(this.combinations[i]) || [])
+			const conflicts = (Engine.GetConflicts(this.combinations[i]) || [])
 				.filter(name => name != this.name).map(translate);
 			if (conflicts.length)
 				Engine.GetGUIObjectByName("conflicts[" + i + "]").caption =
diff --git a/binaries/data/mods/public/gui/hotkeys/HotkeysPage.js b/binaries/data/mods/public/gui/hotkeys/HotkeysPage.js
index 0e87724c77..ec3f8cc161 100644
--- a/binaries/data/mods/public/gui/hotkeys/HotkeysPage.js
+++ b/binaries/data/mods/public/gui/hotkeys/HotkeysPage.js
@@ -5,8 +5,8 @@ class HotkeysPage
 		this.metadata = metadata;
 
 		Engine.GetGUIObjectByName("hotkeyList").onMouseLeftDoubleClickItem = () => {
-			let idx = Engine.GetGUIObjectByName("hotkeyList").selected;
-			let picker = new HotkeyPicker(
+			const idx = Engine.GetGUIObjectByName("hotkeyList").selected;
+			const picker = new HotkeyPicker(
 				this.metadata,
 				this.onHotkeyPicked.bind(this),
 				Engine.GetGUIObjectByName("hotkeyList").list_data[idx],
@@ -37,30 +37,30 @@ class HotkeysPage
 
 	setupHotkeyData()
 	{
-		let hotkeydata = Engine.GetHotkeyMap();
+		const hotkeydata = Engine.GetHotkeyMap();
 		this.hotkeys = hotkeydata;
-		let categories = clone(this.metadata.categories);
-		for (let name in categories)
+		const categories = clone(this.metadata.categories);
+		for (const name in categories)
 			categories[name].hotkeys = [];
 		// Add hotkeys defined in the metadata but not in the C++ map.
-		for (let hotkeyName in this.metadata.hotkeys)
+		for (const hotkeyName in this.metadata.hotkeys)
 			if (!this.hotkeys[hotkeyName])
 				this.hotkeys[hotkeyName] = [];
-		for (let hotkeyName in this.hotkeys)
+		for (const hotkeyName in this.hotkeys)
 		{
 			if (this.metadata.hotkeys[hotkeyName])
-				for (let cat of this.metadata.hotkeys[hotkeyName].categories)
+				for (const cat of this.metadata.hotkeys[hotkeyName].categories)
 					categories[cat].hotkeys.push(hotkeyName);
 			else
 				categories[this.metadata.DEFAULT_CATEGORY].hotkeys.push(hotkeyName);
 		}
-		for (let cat in categories)
+		for (const cat in categories)
 			categories[cat].hotkeys.sort((a, b) => {
 				if (!this.metadata.hotkeys[a] || !this.metadata.hotkeys[b])
 					return !this.metadata.hotkeys[a] ? 1 : -1;
 				return this.metadata.hotkeys[a].order - this.metadata.hotkeys[b].order;
 			});
-		for (let cat in categories)
+		for (const cat in categories)
 			if (categories[cat].hotkeys.length === 0)
 				delete categories[cat];
 		this.categories = categories;
@@ -68,9 +68,9 @@ class HotkeysPage
 
 	setupFilters()
 	{
-		let dropdown = Engine.GetGUIObjectByName("hotkeyFilter");
-		let names = [];
-		for (let cat in this.categories)
+		const dropdown = Engine.GetGUIObjectByName("hotkeyFilter");
+		const names = [];
+		for (const cat in this.categories)
 			names.push(translateWithContext("hotkey metadata", this.categories[cat].name));
 		dropdown.list = [translate("All Hotkeys")].concat(names);
 		dropdown.list_data = [-1].concat(Object.keys(this.categories));
@@ -79,12 +79,12 @@ class HotkeysPage
 
 	setupHotkeyList()
 	{
-		let hotkeyList = Engine.GetGUIObjectByName("hotkeyList");
+		const hotkeyList = Engine.GetGUIObjectByName("hotkeyList");
 		hotkeyList.selected = -1;
-		let textFilter = Engine.GetGUIObjectByName("hotkeyTextFilter").caption.toLowerCase();
+		const textFilter = Engine.GetGUIObjectByName("hotkeyTextFilter").caption.toLowerCase();
 
 		let hotkeys;
-		let dropdown = Engine.GetGUIObjectByName("hotkeyFilter");
+		const dropdown = Engine.GetGUIObjectByName("hotkeyFilter");
 		if (dropdown.selected && dropdown.selected !== 0)
 			hotkeys = this.categories[dropdown.list_data[dropdown.selected]].hotkeys;
 		else
@@ -102,7 +102,7 @@ class HotkeysPage
 
 	onFilterHover()
 	{
-		let dropdown = Engine.GetGUIObjectByName("hotkeyFilter");
+		const dropdown = Engine.GetGUIObjectByName("hotkeyFilter");
 		if (dropdown.hovered === -1)
 			dropdown.tooltip = "";
 		else if (dropdown.hovered === 0)
@@ -113,12 +113,12 @@ class HotkeysPage
 
 	onHotkeyHover()
 	{
-		let hotkeyList = Engine.GetGUIObjectByName("hotkeyList");
+		const hotkeyList = Engine.GetGUIObjectByName("hotkeyList");
 		if (hotkeyList.hovered === -1)
 			hotkeyList.tooltip = "";
 		else
 		{
-			let hotkey = hotkeyList.list_data[hotkeyList.hovered];
+			const hotkey = hotkeyList.list_data[hotkeyList.hovered];
 			hotkeyList.tooltip = this.metadata.hotkeys[hotkey]?.desc ?
 				translateWithContext("hotkey metadata", this.metadata.hotkeys[hotkey]?.desc) :
 				translate(this.UnavailableTooltipString);
@@ -163,13 +163,13 @@ class HotkeysPage
 
 	saveUserHotkeys()
 	{
-		for (let hotkey in this.hotkeys)
+		for (const hotkey in this.hotkeys)
 			Engine.ConfigDB_RemoveValue("user", "hotkey." + hotkey);
 		Engine.ReloadHotkeys();
-		let defaultData = Engine.GetHotkeyMap();
-		for (let hotkey in this.hotkeys)
+		const defaultData = Engine.GetHotkeyMap();
+		for (const hotkey in this.hotkeys)
 		{
-			let keymap = formatHotkeyCombinations(this.hotkeys[hotkey], false);
+			const keymap = formatHotkeyCombinations(this.hotkeys[hotkey], false);
 			if (keymap.join("") !== formatHotkeyCombinations(defaultData[hotkey], false).join(""))
 				Engine.ConfigDB_CreateValues("user", "hotkey." + hotkey, keymap);
 		}
diff --git a/binaries/data/mods/public/gui/loadgame/SavegameDeleter.js b/binaries/data/mods/public/gui/loadgame/SavegameDeleter.js
index 0dbd2ab82e..5b3de424f2 100644
--- a/binaries/data/mods/public/gui/loadgame/SavegameDeleter.js
+++ b/binaries/data/mods/public/gui/loadgame/SavegameDeleter.js
@@ -59,7 +59,7 @@ class SavegameDeleter
 		if (!Engine.DeleteSavedGame(gameID))
 			error("Could not delete saved game: " + gameID);
 
-		for (let handler of this.savegameListChangeHandlers)
+		for (const handler of this.savegameListChangeHandlers)
 			handler.onSavegameListChange();
 	}
 }
diff --git a/binaries/data/mods/public/gui/loadgame/SavegameList.js b/binaries/data/mods/public/gui/loadgame/SavegameList.js
index ad88bc18e0..786fec1912 100644
--- a/binaries/data/mods/public/gui/loadgame/SavegameList.js
+++ b/binaries/data/mods/public/gui/loadgame/SavegameList.js
@@ -31,15 +31,15 @@ class SavegameList
 
 	initSavegameList()
 	{
-		let engineInfo = Engine.GetEngineInfo();
+		const engineInfo = Engine.GetEngineInfo();
 
 		this.gameSelection.onSelectionColumnChange = () => { this.updateSavegameList(); };
 		this.gameSelection.onMouseLeftDoubleClickItem = () => { this.confirmButton.onPress(); };
 		this.gameSelection.onSelectionChange = () => {
-			let gameId = this.gameSelection.list_data[this.gameSelection.selected];
-			let metadata = this.savedGamesMetadata[this.gameSelection.selected];
-			let label = this.generateSavegameLabel(metadata, engineInfo);
-			for (let handler of this.selectionChangeHandlers)
+			const gameId = this.gameSelection.list_data[this.gameSelection.selected];
+			const metadata = this.savedGamesMetadata[this.gameSelection.selected];
+			const label = this.generateSavegameLabel(metadata, engineInfo);
+			for (const handler of this.selectionChangeHandlers)
 				handler.onSelectionChange(gameId, metadata, label);
 		};
 
@@ -71,7 +71,7 @@ class SavegameList
 		let savedGames = Engine.GetSavedGames();
 
 		// Get current game version and loaded mods
-		let engineInfo = Engine.GetEngineInfo();
+		const engineInfo = Engine.GetEngineInfo();
 
 		if (this.compatibilityFilter.checked)
 			savedGames = savedGames.filter(game => {
@@ -85,7 +85,7 @@ class SavegameList
 		this.gameSelection.enabled = !!savedGames.length;
 		this.gameSelectionFeedback.hidden = !!savedGames.length;
 
-		let selectedGameId = this.gameSelection.list_data[this.gameSelection.selected];
+		const selectedGameId = this.gameSelection.list_data[this.gameSelection.selected];
 
 		// Save metadata for the detailed view
 		this.savedGamesMetadata = savedGames.map(game => {
@@ -93,8 +93,8 @@ class SavegameList
 			return game.metadata;
 		});
 
-		let sortKey = this.gameSelection.selected_column;
-		let sortOrder = this.gameSelection.selected_column_order;
+		const sortKey = this.gameSelection.selected_column;
+		const sortOrder = this.gameSelection.selected_column_order;
 
 		this.savedGamesMetadata = this.savedGamesMetadata.sort((a, b) => {
 			let cmpA, cmpB;
@@ -127,7 +127,7 @@ class SavegameList
 		});
 
 		let list = this.savedGamesMetadata.map(metadata => {
-			let isCompatible = this.isCompatibleSavegame(metadata, engineInfo) &&
+			const isCompatible = this.isCompatibleSavegame(metadata, engineInfo) &&
 			                   this.campaignFilter(metadata, this.campaignRun);
 			// Backwards compatibility for pre-A25 savegames
 			const mapName = metadata.initAttributes.settings?.mapName ?? metadata.initAttributes.settings.Name;
@@ -153,7 +153,7 @@ class SavegameList
 
 		 // Restore selection if the selected savegame still exists.
 		// If the last savegame was deleted, or if it was hidden by the compatibility filter, select the new last item.
-		let selectedGameIndex = this.savedGamesMetadata.findIndex(metadata => metadata.id == selectedGameId);
+		const selectedGameIndex = this.savedGamesMetadata.findIndex(metadata => metadata.id == selectedGameId);
 		if (selectedGameIndex != -1)
 			this.gameSelection.selected = selectedGameIndex;
 		else if (this.gameSelection.selected >= this.savedGamesMetadata.length)
diff --git a/binaries/data/mods/public/gui/loadgame/SavegameLoader.js b/binaries/data/mods/public/gui/loadgame/SavegameLoader.js
index 30f3617e75..c8de3ee389 100644
--- a/binaries/data/mods/public/gui/loadgame/SavegameLoader.js
+++ b/binaries/data/mods/public/gui/loadgame/SavegameLoader.js
@@ -22,9 +22,9 @@ class SavegameLoader
 	async loadGame(gameId, metadata)
 	{
 		// Check compatibility before really loading it
-		let engineInfo = Engine.GetEngineInfo();
-		let sameMods = hasSameMods(metadata.mods, engineInfo.mods);
-		let sameEngineVersion = metadata.engine_version && metadata.engine_version == engineInfo.engine_version;
+		const engineInfo = Engine.GetEngineInfo();
+		const sameMods = hasSameMods(metadata.mods, engineInfo.mods);
+		const sameEngineVersion = metadata.engine_version && metadata.engine_version == engineInfo.engine_version;
 
 		if (sameEngineVersion && sameMods)
 		{
diff --git a/binaries/data/mods/public/gui/loadgame/SavegamePage.js b/binaries/data/mods/public/gui/loadgame/SavegamePage.js
index 74d260be93..03d64092a5 100644
--- a/binaries/data/mods/public/gui/loadgame/SavegamePage.js
+++ b/binaries/data/mods/public/gui/loadgame/SavegamePage.js
@@ -20,7 +20,7 @@ class SavegamePage
 		{
 			this.savegameWriter = new SavegameWriter(closePageCallback, data.savedGameData);
 			this.savegameList.registerSelectionChangeHandler(this.savegameWriter);
-			let size = this.savegameList.gameSelection.size;
+			const size = this.savegameList.gameSelection.size;
 			size.bottom -= 24;
 			this.savegameList.gameSelection.size = size;
 		}
diff --git a/binaries/data/mods/public/gui/loadgame/SavegameWriter.js b/binaries/data/mods/public/gui/loadgame/SavegameWriter.js
index 6e0242b270..156ccb5bec 100644
--- a/binaries/data/mods/public/gui/loadgame/SavegameWriter.js
+++ b/binaries/data/mods/public/gui/loadgame/SavegameWriter.js
@@ -9,7 +9,7 @@ class SavegameWriter
 		this.closePageCallback = closePageCallback;
 		this.savedGameData = savedGameData;
 
-		let saveNew = () => {
+		const saveNew = () => {
 			this.saveGame();
 		};
 
@@ -37,8 +37,8 @@ class SavegameWriter
 
 	async saveGame(gameID, label)
 	{
-		let desc = this.saveGameDesc.caption;
-		let name = gameID || "savegame";
+		const desc = this.saveGameDesc.caption;
+		const name = gameID || "savegame";
 
 		if (gameID)
 		{
@@ -53,7 +53,7 @@ class SavegameWriter
 				return;
 		}
 
-		let simulationState = Engine.GuiInterfaceCall("GetSimulationState");
+		const simulationState = Engine.GuiInterfaceCall("GetSimulationState");
 		this.savedGameData.timeElapsed = simulationState.timeElapsed;
 		this.savedGameData.states = simulationState.players.map(pState => pState.state);
 
diff --git a/binaries/data/mods/public/gui/loading/ProgressBar.js b/binaries/data/mods/public/gui/loading/ProgressBar.js
index 990d989640..552404b2ad 100644
--- a/binaries/data/mods/public/gui/loading/ProgressBar.js
+++ b/binaries/data/mods/public/gui/loading/ProgressBar.js
@@ -25,7 +25,7 @@ class ProgressBar
 			return;
 
 		// Show 100 when it is really 99
-		let progress = progression + 1;
+		const progress = progression + 1;
 		this.progressbar.progress = progress;
 
 		if (this.showDescription)
@@ -36,8 +36,8 @@ class ProgressBar
 			this.progressText.caption = sprintf(this.CaptionFormat, this.percentArgs);
 		}
 
-		let increment = Math.round(progress * this.progressBarSize / 100);
-		let size = this.progressbar_right.size;
+		const increment = Math.round(progress * this.progressBarSize / 100);
+		const size = this.progressbar_right.size;
 		size.left = increment;
 		size.right = increment + this.progressbar_right_width;
 		this.progressbar_right.size = size;
diff --git a/binaries/data/mods/public/gui/loading/TitleDisplay.js b/binaries/data/mods/public/gui/loading/TitleDisplay.js
index 405b66c4b2..56f278fa8a 100644
--- a/binaries/data/mods/public/gui/loading/TitleDisplay.js
+++ b/binaries/data/mods/public/gui/loading/TitleDisplay.js
@@ -5,7 +5,7 @@ class TitleDisplay
 {
 	constructor(data)
 	{
-		let loadingMapName = Engine.GetGUIObjectByName("loadingMapName");
+		const loadingMapName = Engine.GetGUIObjectByName("loadingMapName");
 		loadingMapName.caption = sprintf(
 			data.attribs.mapType == "random" ? this.Generating : this.Loading,
 			{ "map": translate(data.attribs.settings.mapName) });
diff --git a/binaries/data/mods/public/gui/locale/locale.js b/binaries/data/mods/public/gui/locale/locale.js
index 27a642aae7..f482796b3c 100644
--- a/binaries/data/mods/public/gui/locale/locale.js
+++ b/binaries/data/mods/public/gui/locale/locale.js
@@ -45,7 +45,7 @@ function languageSelectionChanged()
 
 async function openAdvancedMenu()
 {
-	let localeText = Engine.GetGUIObjectByName("localeText");
+	const localeText = Engine.GetGUIObjectByName("localeText");
 	const locale = await Engine.OpenChildPage("page_locale_advanced.xml", { "locale": localeText.caption });
 
 	if (!locale)
diff --git a/binaries/data/mods/public/gui/locale_advanced/locale_advanced.js b/binaries/data/mods/public/gui/locale_advanced/locale_advanced.js
index 1e926916b2..7ee49a8a25 100644
--- a/binaries/data/mods/public/gui/locale_advanced/locale_advanced.js
+++ b/binaries/data/mods/public/gui/locale_advanced/locale_advanced.js
@@ -1,17 +1,17 @@
 function init(initData)
 {
-	let languageList = Engine.GetGUIObjectByName("languageList");
-	let countryList = Engine.GetGUIObjectByName("countryList");
-	let resultingLocaleText = Engine.GetGUIObjectByName("resultingLocale");
-	let scriptInput = Engine.GetGUIObjectByName("scriptInput");
+	const languageList = Engine.GetGUIObjectByName("languageList");
+	const countryList = Engine.GetGUIObjectByName("countryList");
+	const resultingLocaleText = Engine.GetGUIObjectByName("resultingLocale");
+	const scriptInput = Engine.GetGUIObjectByName("scriptInput");
 
 	// get languageList data. Only list languages for which we have a dictionary.
-	let languageListData = [];
-	let languageListTmp = Engine.GetSupportedLocaleBaseNames();
-	let currentLocaleLanguage = Engine.GetLocaleLanguage(initData.locale);
+	const languageListData = [];
+	const languageListTmp = Engine.GetSupportedLocaleBaseNames();
+	const currentLocaleLanguage = Engine.GetLocaleLanguage(initData.locale);
 	for (let i = 0; i < languageListTmp.length; ++i)
 	{
-		let lang = Engine.GetLocaleLanguage(languageListTmp[i]);
+		const lang = Engine.GetLocaleLanguage(languageListTmp[i]);
 		if (lang != "" && languageListData.indexOf(lang) == -1)
 			languageListData.push(lang);
 	}
@@ -23,7 +23,7 @@ function init(initData)
 	var currentLocaleCountry = Engine.GetLocaleCountry(initData.locale);
 	for (let i = 0; i < countryListTmp.length; ++i)
 	{
-		let country = Engine.GetLocaleCountry(countryListTmp[i]);
+		const country = Engine.GetLocaleCountry(countryListTmp[i]);
 		if (country != "" && countryListData.indexOf(country) == -1)
 			countryListData.push(country);
 	}
@@ -78,11 +78,11 @@ function updateResultingLocale()
 	if (countryList.selected != -1 && countryList.list_data[countryList.selected] != translateWithContext("localeCountry", "None"))
 		resultingLocaleTmp = resultingLocaleTmp + "_" + countryList.list_data[countryList.selected];
 
-	let acceptButton = Engine.GetGUIObjectByName("acceptButton");
+	const acceptButton = Engine.GetGUIObjectByName("acceptButton");
 	if (Engine.ValidateLocale(resultingLocaleTmp))
 	{
 		resultingLocaleText.caption = resultingLocaleTmp;
-		let dictionaryFileList = Engine.GetDictionariesForLocale(Engine.GetDictionaryLocale(resultingLocaleTmp));
+		const dictionaryFileList = Engine.GetDictionariesForLocale(Engine.GetDictionaryLocale(resultingLocaleTmp));
 		let dictionaryFileString = "";
 		dictionaryFileList.forEach(entry => { dictionaryFileString = dictionaryFileString + entry + "\n"; });
 		dictionaryFile.caption = dictionaryFileString;
diff --git a/binaries/data/mods/public/gui/manual/manual.js b/binaries/data/mods/public/gui/manual/manual.js
index 1b042af7c2..be410c416a 100644
--- a/binaries/data/mods/public/gui/manual/manual.js
+++ b/binaries/data/mods/public/gui/manual/manual.js
@@ -1,9 +1,9 @@
 function init()
 {
-	let mainText = Engine.GetGUIObjectByName("mainText");
-	let text = Engine.TranslateLines(Engine.ReadFile("gui/manual/intro.txt"));
+	const mainText = Engine.GetGUIObjectByName("mainText");
+	const text = Engine.TranslateLines(Engine.ReadFile("gui/manual/intro.txt"));
 
-	let hotkeys = Engine.GetHotkeyMap();
+	const hotkeys = Engine.GetHotkeyMap();
 
 	// Replace anything starting with 'hotkey.' with its hotkey.
 	mainText.caption = text.replace(/hotkey\.([a-z0-9_\.]+)/g, (_, k) => formatHotkeyCombinations(hotkeys[k]));
diff --git a/binaries/data/mods/public/gui/options/options.js b/binaries/data/mods/public/gui/options/options.js
index 01ae2ed3a3..7d767cc6b0 100644
--- a/binaries/data/mods/public/gui/options/options.js
+++ b/binaries/data/mods/public/gui/options/options.js
@@ -93,8 +93,8 @@ var g_OptionType = {
 		"guiToValue": control => control.caption,
 		"guiSetter": "onTextEdit",
 		"sanitizeValue": (value, control, option) => {
-			let color = guiToRgbColor(value);
-			let sanitized = rgbToGuiColor(color);
+			const color = guiToRgbColor(value);
+			const sanitized = rgbToGuiColor(color);
 			if (control)
 			{
 				control.sprite = sanitized == value ? "ModernDarkBoxWhite" : "ModernDarkBoxWhiteInvalid";
@@ -116,7 +116,7 @@ var g_OptionType = {
 		"guiToValue": control => control.caption,
 		"guiSetter": "onTextEdit",
 		"sanitizeValue": (value, control, option) => {
-			let sanitized =
+			const sanitized =
 				Math.min(option.max !== undefined ? option.max : +Infinity,
 					Math.max(option.min !== undefined ? option.min : -Infinity,
 						isNaN(+value) ? 0 : value));
@@ -152,7 +152,7 @@ var g_OptionType = {
 			control.list = option.list.map(e => e.label);
 			control.list_data = option.list.map(e => e.value);
 			control.onHoverChange = () => {
-				let item = option.list[control.hovered];
+				const item = option.list[control.hovered];
 				control.tooltip = item && item.tooltip || option.tooltip;
 			};
 		}
@@ -248,10 +248,10 @@ function getHotloadData()
 function displayOptions()
 {
 	// Hide all controls
-	for (let body of Engine.GetGUIObjectByName("option_controls").children)
+	for (const body of Engine.GetGUIObjectByName("option_controls").children)
 	{
 		body.hidden = true;
-		for (let control of body.children)
+		for (const control of body.children)
 			control.hidden = true;
 	}
 
@@ -259,20 +259,20 @@ function displayOptions()
 	for (let i = 0; i < g_Options[g_TabCategorySelected].options.length; ++i)
 	{
 		// Position vertically
-		let body = Engine.GetGUIObjectByName("option_control[" + i + "]");
-		let bodySize = body.size;
+		const body = Engine.GetGUIObjectByName("option_control[" + i + "]");
+		const bodySize = body.size;
 		bodySize.top = g_OptionControlOffset + i * (g_OptionControlHeight + g_OptionControlDist);
 		bodySize.bottom = bodySize.top + g_OptionControlHeight;
 		body.size = bodySize;
 		body.hidden = false;
 
 		// Load option data
-		let option = g_Options[g_TabCategorySelected].options[i];
-		let optionType = g_OptionType[option.type];
-		let value = optionType.configToValue(Engine.ConfigDB_GetValue("user", option.config));
+		const option = g_Options[g_TabCategorySelected].options[i];
+		const optionType = g_OptionType[option.type];
+		const value = optionType.configToValue(Engine.ConfigDB_GetValue("user", option.config));
 
 		// Setup control
-		let control = Engine.GetGUIObjectByName("option_control_" + option.type + "[" + i + "]");
+		const control = Engine.GetGUIObjectByName("option_control_" + option.type + "[" + i + "]");
 		control.tooltip = option.tooltip + (optionType.tooltip ? "\n" + optionType.tooltip(value, option) : "");
 		control.hidden = false;
 
@@ -286,7 +286,7 @@ function displayOptions()
 
 		control[optionType.guiSetter] = function() {
 
-			let value = optionType.guiToValue(control);
+			const value = optionType.guiToValue(control);
 
 			if (optionType.sanitizeValue)
 				optionType.sanitizeValue(value, control, option);
@@ -311,12 +311,12 @@ function displayOptions()
 		};
 
 		// Setup label
-		let label = Engine.GetGUIObjectByName("option_label[" + i + "]");
+		const label = Engine.GetGUIObjectByName("option_label[" + i + "]");
 		label.caption = option.label;
 		label.tooltip = option.tooltip;
 		label.hidden = false;
 
-		let labelSize = label.size;
+		const labelSize = label.size;
 		labelSize.left = option.dependencies ? g_DependentLabelIndentation : 0;
 		labelSize.rright = control.size.rleft;
 		label.size = labelSize;
@@ -373,8 +373,8 @@ async function setDefaults()
 	if (buttonIndex === 0)
 		return;
 
-	for (let category in g_Options)
-		for (let option of g_Options[category].options)
+	for (const category in g_Options)
+		for (const option of g_Options[category].options)
 		{
 			Engine.ConfigDB_RemoveValue("user", option.config);
 			g_ChangedKeys.add(option.config);
@@ -401,8 +401,8 @@ function revertChanges()
 {
 	Engine.ConfigDB_Reload("user");
 
-	for (let category in g_Options)
-		for (let option of g_Options[category].options)
+	for (const category in g_Options)
+		for (const option of g_Options[category].options)
 			if (option.function)
 				Engine[option.function](
 					g_OptionType[option.type].configToValue(
@@ -415,11 +415,11 @@ async function saveChanges()
 {
 	const category = Object.keys(g_Options).find(key => {
 		return g_Options[key].options.some(option => {
-			let optionType = g_OptionType[option.type];
+			const optionType = g_OptionType[option.type];
 			if (!optionType.sanitizeValue)
 				return false;
 
-			let value = optionType.configToValue(Engine.ConfigDB_GetValue("user", option.config));
+			const value = optionType.configToValue(Engine.ConfigDB_GetValue("user", option.config));
 			return value != optionType.sanitizeValue(value, undefined, option);
 		});
 	});
diff --git a/binaries/data/mods/public/gui/pregame/BackgroundHandler.js b/binaries/data/mods/public/gui/pregame/BackgroundHandler.js
index c565b703d8..a379453be1 100644
--- a/binaries/data/mods/public/gui/pregame/BackgroundHandler.js
+++ b/binaries/data/mods/public/gui/pregame/BackgroundHandler.js
@@ -15,14 +15,14 @@ class BackgroundHandler
 
 	onWindowResized()
 	{
-		let size = this.backgrounds.getComputedSize();
+		const size = this.backgrounds.getComputedSize();
 		this.backgroundsSize = deepfreeze(new GUISize(size.top, size.left, size.right, size.bottom));
 	}
 
 	onTick()
 	{
-		let time = Date.now() - this.initTime;
-		for (let background of this.backgroundLayers)
+		const time = Date.now() - this.initTime;
+		for (const background of this.backgroundLayers)
 			background.update(time, this.backgroundsSize);
 	}
 }
@@ -41,13 +41,13 @@ class BackgroundLayer
 
 	update(time, backgroundsSize)
 	{
-		let height = backgroundsSize.bottom - backgroundsSize.top;
-		let width = height * this.AspectRatio;
-		let offset = this.layer.offset(time / 1000, width);
+		const height = backgroundsSize.bottom - backgroundsSize.top;
+		const width = height * this.AspectRatio;
+		const offset = this.layer.offset(time / 1000, width);
 
 		if (this.layer.tiling)
 		{
-			let iw = height * 2;
+			const iw = height * 2;
 			let left = offset % iw;
 			if (left >= 0)
 				left -= iw;
@@ -59,7 +59,7 @@ class BackgroundLayer
 		}
 		else
 		{
-			let right = backgroundsSize.right / 2 + offset;
+			const right = backgroundsSize.right / 2 + offset;
 			this.background.size = new GUISize(
 				right - height,
 				backgroundsSize.top,
diff --git a/binaries/data/mods/public/gui/pregame/MainMenuItemHandler.js b/binaries/data/mods/public/gui/pregame/MainMenuItemHandler.js
index ab3a1fe1c7..da8ff10c31 100644
--- a/binaries/data/mods/public/gui/pregame/MainMenuItemHandler.js
+++ b/binaries/data/mods/public/gui/pregame/MainMenuItemHandler.js
@@ -28,7 +28,7 @@ class MainMenuItemHandler
 	setupMenuButtons(buttons, menuItems)
 	{
 		buttons.forEach((button, i) => {
-			let item = menuItems[i];
+			const item = menuItems[i];
 			button.hidden = !item;
 			if (button.hidden)
 				return;
@@ -82,9 +82,9 @@ class MainMenuItemHandler
 
 	setupHotkeys(menuItems)
 	{
-		for (let i in menuItems)
+		for (const i in menuItems)
 		{
-			let item = menuItems[i];
+			const item = menuItems[i];
 			if (item.onPress && item.hotkey)
 				Engine.SetGlobalHotkey(item.hotkey, "Press", () => {
 					this.closeSubmenu();
@@ -100,7 +100,7 @@ class MainMenuItemHandler
 	{
 		this.setupMenuButtons(this.submenuButtons.children, this.menuItems[i].submenu);
 
-		let top = this.mainMenuButtons.children[i].getComputedSize().top;
+		const top = this.mainMenuButtons.children[i].getComputedSize().top;
 
 		this.submenu.size = new GUISize(
 			this.submenu.size.left, top - this.Margin,
@@ -109,14 +109,14 @@ class MainMenuItemHandler
 		this.submenu.hidden = false;
 
 		{
-			let size = this.MainMenuPanelRightBorderTop.size;
+			const size = this.MainMenuPanelRightBorderTop.size;
 			size.bottom = this.submenu.size.top + this.Margin;
 			size.rbottom = 0;
 			this.MainMenuPanelRightBorderTop.size = size;
 		}
 
 		{
-			let size = this.MainMenuPanelRightBorderBottom.size;
+			const size = this.MainMenuPanelRightBorderBottom.size;
 			size.top = this.submenu.size.bottom;
 			this.MainMenuPanelRightBorderBottom.size = size;
 		}
@@ -131,7 +131,7 @@ class MainMenuItemHandler
 		this.submenu.hidden = true;
 		this.submenu.size = this.mainMenu.size;
 
-		let size = this.MainMenuPanelRightBorderTop.size;
+		const size = this.MainMenuPanelRightBorderTop.size;
 		size.top = 0;
 		size.bottom = 0;
 		size.rbottom = 100;
@@ -140,12 +140,12 @@ class MainMenuItemHandler
 
 	onTick()
 	{
-		let now = Date.now();
+		const now = Date.now();
 		if (now == this.lastTickTime)
 			return;
 
-		let maxOffset = this.mainMenu.size.right - this.submenu.size.left;
-		let offset = Math.min(this.MenuSpeed * (now - this.lastTickTime), maxOffset);
+		const maxOffset = this.mainMenu.size.right - this.submenu.size.left;
+		const offset = Math.min(this.MenuSpeed * (now - this.lastTickTime), maxOffset);
 
 		this.lastTickTime = now;
 
@@ -155,7 +155,7 @@ class MainMenuItemHandler
 			return;
 		}
 
-		let size = this.submenu.size;
+		const size = this.submenu.size;
 		size.left += offset;
 		size.right += offset;
 		this.submenu.size = size;
diff --git a/binaries/data/mods/public/gui/pregame/MainMenuPage.js b/binaries/data/mods/public/gui/pregame/MainMenuPage.js
index 7c7d343944..1c1501f20d 100644
--- a/binaries/data/mods/public/gui/pregame/MainMenuPage.js
+++ b/binaries/data/mods/public/gui/pregame/MainMenuPage.js
@@ -36,8 +36,8 @@ class ProjectInformationHandler
 {
 	constructor(projectInformation)
 	{
-		for (let objectName in projectInformation)
-			for (let propertyName in projectInformation[objectName])
+		for (const objectName in projectInformation)
+			for (const propertyName in projectInformation[objectName])
 				Engine.GetGUIObjectByName(objectName)[propertyName] = projectInformation[objectName][propertyName];
 	}
 }
@@ -46,12 +46,12 @@ class CommunityButtonHandler
 {
 	constructor(communityButtons)
 	{
-		let buttons = Engine.GetGUIObjectByName("communityButtons").children;
+		const buttons = Engine.GetGUIObjectByName("communityButtons").children;
 
 		communityButtons.forEach((buttonInfo, i) => {
-			let button = buttons[i];
+			const button = buttons[i];
 			button.hidden = false;
-			for (let propertyName in buttonInfo)
+			for (const propertyName in buttonInfo)
 				button[propertyName] = buttonInfo[propertyName];
 		});
 
diff --git a/binaries/data/mods/public/gui/pregame/userreport/userreport.js b/binaries/data/mods/public/gui/pregame/userreport/userreport.js
index 632f915b4b..fce85f43e3 100644
--- a/binaries/data/mods/public/gui/pregame/userreport/userreport.js
+++ b/binaries/data/mods/public/gui/pregame/userreport/userreport.js
@@ -55,9 +55,9 @@ function setUserReportEnabled(enabled)
 
 function updateUserReportButtons()
 {
-	let termsFeedback = checkTerms();
+	const termsFeedback = checkTerms();
 
-	let userReportEnableButton = Engine.GetGUIObjectByName("userReportEnableButton");
+	const userReportEnableButton = Engine.GetGUIObjectByName("userReportEnableButton");
 	userReportEnableButton.caption = Engine.IsUserReportEnabled() ? translate("Disable Feedback") : translate("Enable Feedback");
 	userReportEnableButton.enabled = !termsFeedback;
 	userReportEnableButton.tooltip = termsFeedback;
@@ -65,7 +65,7 @@ function updateUserReportButtons()
 		setUserReportEnabled(!Engine.IsUserReportEnabled());
 	};
 
-	let userReportTermsButton = Engine.GetGUIObjectByName("userReportTermsButton");
+	const userReportTermsButton = Engine.GetGUIObjectByName("userReportTermsButton");
 	userReportTermsButton.caption = g_TermsUserReport.TermsAndConditions.title;
 	userReportTermsButton.onPress = () => {
 		openTerms("TermsAndConditions");
@@ -74,7 +74,7 @@ function updateUserReportButtons()
 
 function updateUserReportStatus()
 {
-	let statusData = Engine.GetUserReportStatus().split(":");
+	const statusData = Engine.GetUserReportStatus().split(":");
 
 	Engine.GetGUIObjectByName("userReportText").caption =
 		Engine.IsUserReportEnabled() ?
diff --git a/binaries/data/mods/public/gui/prelobby/common/credentials/credentials.js b/binaries/data/mods/public/gui/prelobby/common/credentials/credentials.js
index 02665ec5c0..985a6167a7 100644
--- a/binaries/data/mods/public/gui/prelobby/common/credentials/credentials.js
+++ b/binaries/data/mods/public/gui/prelobby/common/credentials/credentials.js
@@ -1,6 +1,6 @@
 function checkUsername(register)
 {
-	let username = Engine.GetGUIObjectByName("username").caption;
+	const username = Engine.GetGUIObjectByName("username").caption;
 	if (!username)
 		return translate("Please enter your username");
 
@@ -12,7 +12,7 @@ function checkUsername(register)
 
 function checkPassword(register)
 {
-	let password = Engine.GetGUIObjectByName("password").caption;
+	const password = Engine.GetGUIObjectByName("password").caption;
 
 	if (!password)
 		return register ?
@@ -27,11 +27,11 @@ function checkPassword(register)
 
 function checkPasswordConfirmation()
 {
-	let password1 = Engine.GetGUIObjectByName("password").caption;
+	const password1 = Engine.GetGUIObjectByName("password").caption;
 	if (!password1)
 		return translate("Please enter your password again");
 
-	let password2 = Engine.GetGUIObjectByName("passwordRepeat").caption;
+	const password2 = Engine.GetGUIObjectByName("passwordRepeat").caption;
 	if (password1 != password2)
 		return translate("Passwords do not match");
 
@@ -46,8 +46,8 @@ function initRememberPassword()
 
 async function toggleRememberPassword()
 {
-	let checkbox = Engine.GetGUIObjectByName("rememberPassword");
-	let enabled = Engine.ConfigDB_GetValue("user", "lobby.rememberpassword") == "true";
+	const checkbox = Engine.GetGUIObjectByName("rememberPassword");
+	const enabled = Engine.ConfigDB_GetValue("user", "lobby.rememberpassword") == "true";
 	if (!checkbox.checked && enabled && Engine.ConfigDB_GetValue("user", "lobby.password"))
 	{
 		const buttonIndex = await messageBox(
@@ -68,8 +68,8 @@ async function toggleRememberPassword()
 
 function getEncryptedPassword()
 {
-	let typedUnencryptedPassword = Engine.GetGUIObjectByName("password").caption;
-	let storedEncryptedPassword = Engine.ConfigDB_GetValue("user", "lobby.password");
+	const typedUnencryptedPassword = Engine.GetGUIObjectByName("password").caption;
+	const storedEncryptedPassword = Engine.ConfigDB_GetValue("user", "lobby.password");
 
 	if (typedUnencryptedPassword == storedEncryptedPassword.substr(0, 10))
 		return storedEncryptedPassword;
@@ -81,7 +81,7 @@ function getEncryptedPassword()
 
 function saveCredentials()
 {
-	let username = Engine.GetGUIObjectByName("username").caption;
+	const username = Engine.GetGUIObjectByName("username").caption;
 	Engine.ConfigDB_CreateValue("user", "playername.multiplayer", username);
 	Engine.ConfigDB_CreateValue("user", "lobby.login", username);
 
diff --git a/binaries/data/mods/public/gui/prelobby/common/feedback/feedback.js b/binaries/data/mods/public/gui/prelobby/common/feedback/feedback.js
index 79af54ef87..6e46edddec 100644
--- a/binaries/data/mods/public/gui/prelobby/common/feedback/feedback.js
+++ b/binaries/data/mods/public/gui/prelobby/common/feedback/feedback.js
@@ -17,11 +17,11 @@ var g_LobbyMessages = {
  */
 function onTick()
 {
-	let messages = Engine.LobbyGuiPollNewMessages();
+	const messages = Engine.LobbyGuiPollNewMessages();
 	if (!messages)
 		return;
 
-	for (let message of messages)
+	for (const message of messages)
 	{
 		if (message.type == "system" && message.level)
 			g_LobbyMessages[message.level](message);
diff --git a/binaries/data/mods/public/gui/prelobby/common/terms/termslobby.js b/binaries/data/mods/public/gui/prelobby/common/terms/termslobby.js
index 813e9ff53e..258a90a1bb 100644
--- a/binaries/data/mods/public/gui/prelobby/common/terms/termslobby.js
+++ b/binaries/data/mods/public/gui/prelobby/common/terms/termslobby.js
@@ -2,9 +2,9 @@ var g_TermsButtonHeight = 38;
 
 function initLobbyTerms()
 {
-	let termsURL = Engine.ConfigDB_GetValue("user", "lobby.terms_url");
+	const termsURL = Engine.ConfigDB_GetValue("user", "lobby.terms_url");
 
-	let terms = {
+	const terms = {
 		"Service": {
 			"title": translate("Terms of Service"),
 			"instruction": translate("Please read and accept the Terms of Service."),
@@ -39,7 +39,7 @@ function initLobbyTerms()
 
 	Object.keys(terms).forEach((page, i) => {
 
-		let button = Engine.GetGUIObjectByName("termsButton[" + i + "]");
+		const button = Engine.GetGUIObjectByName("termsButton[" + i + "]");
 
 		button.caption = terms[page].title;
 
@@ -47,7 +47,7 @@ function initLobbyTerms()
 			openTerms(page);
 		};
 
-		let size = button.size;
+		const size = button.size;
 		size.top = i * g_TermsButtonHeight;
 		size.bottom = i * g_TermsButtonHeight + 28;
 		button.size = size;