diff --git a/src/js/tabs/landing.js b/src/js/tabs/landing.js
index 9034af6b..27716299 100644
--- a/src/js/tabs/landing.js
+++ b/src/js/tabs/landing.js
@@ -2,7 +2,6 @@
 
 TABS.landing = {};
 TABS.landing.initialize = function (callback) {
-  var self = this;
 
   if (GUI.active_tab != 'landing') {
     GUI.active_tab = 'landing';
@@ -10,10 +9,10 @@ TABS.landing.initialize = function (callback) {
 
   $('#content').load("./tabs/landing.html", function () {
     function showLang(newLang) {
-      var bottomSection = $('.languageSwitcher');
+      bottomSection = $('.languageSwitcher');
       bottomSection.find('a').each(function(index) {
-        var element = $(this);
-        var languageSelected = element.attr('lang');
+        const element = $(this);
+        const languageSelected = element.attr('lang');
         if (newLang == languageSelected) {
           element.removeClass('selected_language');
           element.addClass('selected_language');
@@ -22,18 +21,18 @@ TABS.landing.initialize = function (callback) {
         }
       });
     }
-    var bottomSection = $('.languageSwitcher');
+    let bottomSection = $('.languageSwitcher');
     bottomSection.html(' <span i18n="language_choice_message"></span>');
     bottomSection.append(' <a href="#" i18n="language_default_pretty" lang="DEFAULT"></a>');
-    var languagesAvailables = i18n.getLanguagesAvailables();
+    const languagesAvailables = i18n.getLanguagesAvailables();
     languagesAvailables.forEach(function(element) {
       bottomSection.append(' <a href="#" lang="' + element + '" i18n="language_' + element + '"></a>');
     });
     bottomSection.find('a').each(function(index) {
-      var element = $(this);
+      let element = $(this);
       element.click(function(){
-        var element = $(this);
-        var languageSelected = element.attr('lang');
+        element = $(this);
+        const languageSelected = element.attr('lang');
         if (!languageSelected) { return; }
         if (i18n.selectedLanguage != languageSelected) {
           i18n.changeLanguage(languageSelected);
diff --git a/src/js/tabs/map.js b/src/js/tabs/map.js
index 49aeae7f..ef563ea2 100644
--- a/src/js/tabs/map.js
+++ b/src/js/tabs/map.js
@@ -4,7 +4,7 @@ const DEFAULT_ZOOM = 16,
       ICON_IMAGE = '/images/icons/cf_icon_position.png',
       ICON_IMAGE_NOFIX = '/images/icons/cf_icon_position_nofix.png';
 
-var iconGeometry,
+let iconGeometry,
     map,
     mapView,
     iconStyle,
@@ -15,7 +15,7 @@ window.onload = initializeMap;
 
 function initializeMap() {
 
-    var lonLat = ol.proj.fromLonLat([DEFAULT_LON, DEFAULT_LAT]);
+    const lonLat = ol.proj.fromLonLat([DEFAULT_LON, DEFAULT_LAT]);
 
     mapView = new ol.View({
                         center: lonLat,
@@ -33,14 +33,14 @@ function initializeMap() {
         controls: []
       });
 
-    var icon = new ol.style.Icon(({
+    const icon = new ol.style.Icon(({
         anchor: [0.5, 1],
         opacity: 1,
         scale: 0.5,
         src: ICON_IMAGE
     }));
 
-    var iconNoFix = new ol.style.Icon(({
+    const iconNoFix = new ol.style.Icon(({
         anchor: [0.5, 1],
         opacity: 1,
         scale: 0.5,
@@ -62,11 +62,11 @@ function initializeMap() {
 
     iconFeature.setStyle(iconStyle);
 
-    var vectorSource = new ol.source.Vector({
+    const vectorSource = new ol.source.Vector({
         features: [iconFeature]
     });
 
-    var currentPositionLayer = new ol.layer.Vector({
+    const currentPositionLayer = new ol.layer.Vector({
         source: vectorSource
     });
 
@@ -90,7 +90,7 @@ function processMapEvents(e) {
 
         case 'center':
             iconFeature.setStyle(iconStyle);
-            var center = ol.proj.fromLonLat([e.data.lon, e.data.lat]);
+            const center = ol.proj.fromLonLat([e.data.lon, e.data.lat]);
             mapView.setCenter(center);
             iconGeometry.setCoordinates(center);
             break;
@@ -100,7 +100,7 @@ function processMapEvents(e) {
             break;
         }
 
-  } catch (e) {
-      console.log('Map error ' + e);
+  } catch (err) {
+      console.log(`Map error ${err}`);
   }
 }
diff --git a/src/js/tabs/setup_osd.js b/src/js/tabs/setup_osd.js
index 799b199f..24f10ec4 100644
--- a/src/js/tabs/setup_osd.js
+++ b/src/js/tabs/setup_osd.js
@@ -4,7 +4,6 @@ TABS.setup_osd = {
 };
 
 TABS.setup_osd.initialize = function (callback) {
-    var self = this;
 
     if (GUI.active_tab != 'setup_osd') {
         GUI.active_tab = 'setup_osd';
@@ -25,13 +24,13 @@ TABS.setup_osd.initialize = function (callback) {
     function process_html() {
 
         $('.tab-setup-osd .info').hide(); // requires an MSP update
-        
-        var osdVideoModes = [
+/*      Only used by get_slow_data() which is commented out.
+        const osdVideoModes = new Set([
             'AUTO',
             'NTSC',
             'PAL'
-        ];
-
+        ]);
+*/
         // translate to user-selected language
         i18n.localizePage();
 
@@ -48,10 +47,8 @@ TABS.setup_osd.initialize = function (callback) {
         function get_slow_data() {
             /* FIXME requires MSP update
             MSP.send_message(MSPCodes.MSP_OSD_VIDEO_STATUS, false, false, function () {
-                var element;
-                
-                element = $('.video-mode');
-                var osdVideoMode = osdVideoModes[OSD_VIDEO_STATE.video_mode];
+                let element element = $('.video-mode');
+                const osdVideoMode = osdVideoModes[OSD_VIDEO_STATE.video_mode];
                 element.text(osdVideoMode);
                 
                 element = $('.camera-connected');
diff --git a/src/js/tabs/static_tab.js b/src/js/tabs/static_tab.js
index d26b615c..8626f10d 100644
--- a/src/js/tabs/static_tab.js
+++ b/src/js/tabs/static_tab.js
@@ -2,12 +2,11 @@
 
 TABS.staticTab = {};
 TABS.staticTab.initialize = function (staticTabName, callback) {
-    var self = this;
 
     if (GUI.active_tab != staticTabName) {
         GUI.active_tab = staticTabName;
     }
-    var tabFile = "./tabs/" + staticTabName + ".html";
+    const tabFile = `./tabs/${staticTabName}.html`;
 
     $('#content').html('<div id="tab-static"><div id="tab-static-contents"></div>');
     $('#tab-static-contents').load(tabFile, function () {