diff --git a/keepassxc-browser/background/page.js b/keepassxc-browser/background/page.js
index efe5f8d..a703faf 100755
--- a/keepassxc-browser/background/page.js
+++ b/keepassxc-browser/background/page.js
@@ -103,12 +103,6 @@ page.initOpenedTabs = async function() {
     }
 };
 
-page.isValidProtocol = function(url) {
-    let protocol = url.substring(0, url.indexOf(':'));
-    protocol = protocol.toLowerCase();
-    return !(url.indexOf('.') === -1 || (protocol !== 'http' && protocol !== 'https' && protocol !== 'ftp' && protocol !== 'sftp'));
-};
-
 page.switchTab = function(tab) {
     browserAction.showDefault(tab);
     browser.tabs.sendMessage(tab.id, { action: 'activated_tab' }).catch((e) => {});
diff --git a/keepassxc-browser/content/autocomplete.js b/keepassxc-browser/content/autocomplete.js
index 9ac794f..86020ec 100644
--- a/keepassxc-browser/content/autocomplete.js
+++ b/keepassxc-browser/content/autocomplete.js
@@ -1,6 +1,6 @@
 'use strict';
 
-var kpxcAutocomplete = {};
+const kpxcAutocomplete = {};
 kpxcAutocomplete.autoSubmit = false;
 kpxcAutocomplete.elements = [];
 kpxcAutocomplete.started = false;
diff --git a/keepassxc-browser/content/banner.js b/keepassxc-browser/content/banner.js
index 89cafaa..3bbcc33 100644
--- a/keepassxc-browser/content/banner.js
+++ b/keepassxc-browser/content/banner.js
@@ -2,7 +2,7 @@
 
 const DEFAULT_BROWSER_GROUP = 'KeePassXC-Browser Passwords';
 
-var kpxcBanner = {};
+const kpxcBanner = {};
 kpxcBanner.banner = undefined;
 kpxcBanner.created = false;
 kpxcBanner.credentials = {};
diff --git a/keepassxc-browser/content/define.js b/keepassxc-browser/content/define.js
index baac773..9ea568f 100644
--- a/keepassxc-browser/content/define.js
+++ b/keepassxc-browser/content/define.js
@@ -274,11 +274,7 @@ kpxcDefine.prepareStep3 = function() {
     $('#kpxcDefine-btn-confirm').style.display = 'inline-block';
 };
 
-kpxcDefine.skip = function(e) {
-    if (!e.isTrusted) {
-        return;
-    }
-
+kpxcDefine.skip = function() {
     if (kpxcDefine.dataStep === 1) {
         kpxcDefine.selection.username = null;
         kpxcDefine.prepareStep2();
@@ -290,32 +286,20 @@ kpxcDefine.skip = function(e) {
     }
 };
 
-kpxcDefine.again = function(e) {
-    if (!e.isTrusted) {
-        return;
-    }
-
+kpxcDefine.again = function() {
     kpxcDefine.resetSelection();
     kpxcDefine.prepareStep1();
     kpxcDefine.markAllUsernameFields('#kpxcDefine-fields');
 };
 
-kpxcDefine.more = function(e) {
-    if (!e.isTrusted) {
-        return;
-    }
-
+kpxcDefine.more = function() {
     if (kpxcDefine.dataStep === 2) {
         kpxcDefine.prepareStep2();
         kpxcDefine.markAllPasswordFields('#kpxcDefine-fields', true);
     }
 };
 
-kpxcDefine.confirm = async function(e) {
-    if (!e.isTrusted) {
-        return;
-    }
-
+kpxcDefine.confirm = async function() {
     if (kpxcDefine.dataStep !== 3) {
         return;
     }
@@ -353,11 +337,7 @@ kpxcDefine.confirm = async function(e) {
     kpxcDefine.close();
 };
 
-kpxcDefine.discard = async function(e) {
-    if (!e.isTrusted) {
-        return;
-    }
-
+kpxcDefine.discard = async function() {
     if (!$('#kpxcDefine-btn-discard')) {
         return;
     }
diff --git a/keepassxc-browser/content/keepassxc-browser.js b/keepassxc-browser/content/keepassxc-browser.js
index b0d8940..a73890c 100755
--- a/keepassxc-browser/content/keepassxc-browser.js
+++ b/keepassxc-browser/content/keepassxc-browser.js
@@ -1,13 +1,13 @@
 'use strict';
 
-var ManualFill = {
+const ManualFill = {
     NONE: 0,
     PASS: 1,
     BOTH: 2
 };
 
 // contains already called method names
-var _called = {};
+const _called = {};
 _called.retrieveCredentials = false;
 _called.clearLogins = false;
 _called.manualFillRequested = ManualFill.NONE;
@@ -18,7 +18,7 @@ const _maximumInputs = 100;
 var _detectedFields = 0;
 
 // Element id's containing input fields detected by MutationObserver
-var _observerIds = [];
+const _observerIds = [];
 
 // Document URL
 let _documentURL = document.location.href;
@@ -38,7 +38,7 @@ browser.runtime.onMessage.addListener(async function(req, sender) {
             kpxc.fillInFromActiveElement(false, true); // passOnly to true
         } else if (req.action === 'fill_totp') {
             await kpxc.receiveCredentialsIfNecessary();
-            kpxc.fillInFromActiveElementTOTPOnly(false);
+            kpxc.fillInFromActiveElementTOTPOnly();
         } else if (req.action === 'clear_credentials') {
             kpxcEvents.clearCredentials();
             return Promise.resolve();
@@ -186,7 +186,7 @@ kpxcForm.getNewPassword = function() {
 };
 
 
-var kpxcFields = {};
+const kpxcFields = {};
 kpxcFields.inputQueryPattern = 'input[type=\'text\'], input[type=\'email\'], input[type=\'password\'], input[type=\'tel\'], input[type=\'number\'], input[type=\'username\'], input:not([type])';
 
 // copied from Sizzle.js
@@ -658,10 +658,7 @@ kpxcObserverHelper.getInputs = function(target) {
     // Only include input fields that match with kpxcObserverHelper.inputTypes
     const inputs = [];
     for (const i of inputFields) {
-        let type = i.getAttribute('type');
-        if (type) {
-            type = type.toLowerCase();
-        }
+        let type = i.getLowerCaseAttribute('type');
 
         if (kpxcObserverHelper.inputTypes.includes(type)) {
             inputs.push(i);
@@ -682,7 +679,7 @@ kpxcObserverHelper.ignoredElement = function(target) {
 
     // Ignore KeePassXC-Browser classes
     if (target.className && target.className !== undefined &&
-        (target.className.includes('kpxc') || target.className.includes('ui-helper'))) {
+        target.className.includes('kpxc')) {
         return true;
     }
 
@@ -792,7 +789,7 @@ observer.observe(document, {
     attributeFilter: [ 'style', 'class' ]
 });
 
-var kpxc = {};
+const kpxc = {};
 kpxc.settings = {};
 kpxc.u = null;
 kpxc.p = null;
@@ -970,7 +967,7 @@ kpxc.receiveCredentialsIfNecessary = async function() {
 
         // If the database was locked, this is scope never met. In these cases the response is met at kpxc.detectDatabaseChange
         _called.manualFillRequested = ManualFill.NONE;
-        kpxc.retrieveCredentialsCallback(credentials, false);
+        await kpxc.retrieveCredentialsCallback(credentials, false);
         return credentials;
     }
 
@@ -1195,7 +1192,7 @@ kpxc.fillInCredentials = async function(combination, onlyPassword, suppressWarni
             args: [ kpxc.url, kpxc.submitUrl, true ] // Sets triggerUnlock to true
         });
 
-        kpxc.retrieveCredentialsCallback(credentials, true);
+        await kpxc.retrieveCredentialsCallback(credentials, true);
         kpxc.fillIn(combination, onlyPassword, suppressWarnings);
     }
 };
diff --git a/keepassxc-browser/content/pwgen.js b/keepassxc-browser/content/pwgen.js
index a9b5a8a..d6d2ded 100644
--- a/keepassxc-browser/content/pwgen.js
+++ b/keepassxc-browser/content/pwgen.js
@@ -1,6 +1,6 @@
 'use strict';
 
-var kpxcPassword = {};
+const kpxcPassword = {};
 kpxcPassword.created = false;
 kpxcPassword.icon = null;
 kpxcPassword.inputField = null;
diff --git a/keepassxc-browser/content/sites.js b/keepassxc-browser/content/sites.js
index 0575b16..e96e787 100644
--- a/keepassxc-browser/content/sites.js
+++ b/keepassxc-browser/content/sites.js
@@ -8,7 +8,7 @@ const siteList = [
     }
 ];
 
-var kpxcSites = {};
+const kpxcSites = {};
 
 // Returns a predefined URL for certain sites to ensure compatibility with Site Preferences
 kpxcSites.definedURL = function(url) {
diff --git a/keepassxc-browser/content/ui.js b/keepassxc-browser/content/ui.js
index 96c5ac3..6e6777b 100644
--- a/keepassxc-browser/content/ui.js
+++ b/keepassxc-browser/content/ui.js
@@ -1,16 +1,16 @@
 'use strict';
 
 // jQuery style wrapper for querySelector()
-var $ = function(elem) {
+const $ = function(elem) {
     return document.querySelector(elem);
 };
 
 // Returns a string with 'px' for CSS styles
-var Pixels = function(value) {
+const Pixels = function(value) {
     return String(value) + 'px';
 };
 
-var kpxcUI = {};
+const kpxcUI = {};
 
 // Wrapper for creating elements
 kpxcUI.createElement = function(type, classes, attributes, textContent) {
diff --git a/keepassxc-browser/content/username-field.js b/keepassxc-browser/content/username-field.js
index 02b2463..e2678ca 100644
--- a/keepassxc-browser/content/username-field.js
+++ b/keepassxc-browser/content/username-field.js
@@ -1,6 +1,6 @@
 'use strict';
 
-var kpxcUsernameField = {};
+const kpxcUsernameField = {};
 kpxcUsernameField.icon = null;
 kpxcUsernameField.inputField = null;
 
diff --git a/keepassxc-browser/global.js b/keepassxc-browser/global.js
index e2b635c..6e86adc 100755
--- a/keepassxc-browser/global.js
+++ b/keepassxc-browser/global.js
@@ -8,11 +8,11 @@ const schemeSegment = '(\\*|http|https|ws|wss|file|ftp)';
 const hostSegment = '(\\*|(?:\\*\\.)?(?:[^/*]+))?';
 const pathSegment = '(.*)';
 
-var isFirefox = function() {
+const isFirefox = function() {
     return navigator.userAgent.indexOf('Firefox') !== -1 || navigator.userAgent.indexOf('Gecko/') !== -1;
 };
 
-var showNotification = function(message) {
+const showNotification = function(message) {
     browser.notifications.create({
         'type': 'basic',
         'iconUrl': browser.extension.getURL('icons/keepassxc_64x64.png'),
@@ -21,7 +21,7 @@ var showNotification = function(message) {
     });
 };
 
-var AssociatedAction = {
+const AssociatedAction = {
     NOT_ASSOCIATED: 0,
     ASSOCIATED: 1,
     NEW_ASSOCIATION: 2,
@@ -38,7 +38,7 @@ var AssociatedAction = {
  *
  * https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Match_patterns
  */
-var matchPatternToRegExp = function(pattern) {
+const matchPatternToRegExp = function(pattern) {
     if (pattern === '') {
         return (/^(?:http|https|file|ftp|app):\/\//);
     }
@@ -93,12 +93,12 @@ var matchPatternToRegExp = function(pattern) {
     return new RegExp(regex);
 };
 
-var siteMatch = function(site, url) {
+const siteMatch = function(site, url) {
     const rx = matchPatternToRegExp(site);
     return url.match(rx);
 };
 
-var slashNeededForUrl = function(pattern) {
+const slashNeededForUrl = function(pattern) {
     const matchPattern = new RegExp(`^${schemeSegment}://${hostSegment}$`);
     return matchPattern.exec(pattern);
 };
@@ -108,6 +108,6 @@ function tr(key, params) {
 }
 
 // Removes everything after '?' from URL
-var trimURL = function(url) {
+const trimURL = function(url) {
     return url.indexOf('?') !== -1 ? url.split('?')[0] : url;
 }