diff --git a/eventPage.js b/eventPage.js
index 2d4d7b629b..5f97f1c3a4 100644
--- a/eventPage.js
+++ b/eventPage.js
@@ -10,6 +10,8 @@
     I am using arbitrary dimensions which fixes the Windows 7 problem, hopefully it will get resolved in future release so other OSs won't have to
     use bigger dimensions by default.
 */
+'use strict';
+
 function start_app() {
     chrome.app.window.create('main.html', {
         id: 'main-window',
@@ -79,7 +81,7 @@ chrome.runtime.onInstalled.addListener(function (details) {
         // only fire up notification sequence when one of the major version numbers changed
         if (currentVersionArr[0] != previousVersionArr[0] || currentVersionArr[1] != previousVersionArr[1]) {
             chrome.storage.local.get('update_notify', function (result) {
-                if (typeof result.update_notify === 'undefined' || result.update_notify) {
+                if (!result.update_notify || result.update_notify) {
                     var manifest = chrome.runtime.getManifest();
                     var options = {
                         priority: 0,
diff --git a/js/serial_backend.js b/js/serial_backend.js
index bb3bd090a2..fcabefbe7e 100644
--- a/js/serial_backend.js
+++ b/js/serial_backend.js
@@ -193,7 +193,7 @@ function read_serial(info) {
 
 function sensor_status(sensors_detected) {
     // initialize variable (if it wasn't)
-    if (sensor_status.previous_sensors_detected === 'undefined') {
+    if (!sensor_status.previous_sensors_detected) {
         sensor_status.previous_sensors_detected = 0;
     }
 
diff --git a/main.js b/main.js
index a6fde8b86c..4fa29d3b54 100644
--- a/main.js
+++ b/main.js
@@ -129,7 +129,7 @@ $(document).ready(function () {
 
                 // if notifications are enabled, or wasn't set, check the notifications checkbox
                 chrome.storage.local.get('update_notify', function (result) {
-                    if (result.update_notify === 'undefined' || result.update_notify) {
+                    if (!result.update_notify || result.update_notify) {
                         $('div.notifications input').prop('checked', true);
                     }
                 });