diff --git a/src/convenience.js b/src/convenience.js
index 1fb9ede..054dafe 100644
--- a/src/convenience.js
+++ b/src/convenience.js
@@ -1,3 +1,4 @@
+/* jshint esnext:true */
 /* -*- mode: js -*- */
 /*
   Copyright (c) 2011-2012, Giovanni Campagna <scampa.giovanni@gmail.com>
diff --git a/src/extension.js b/src/extension.js
index dd525d0..60f305b 100644
--- a/src/extension.js
+++ b/src/extension.js
@@ -1,3 +1,4 @@
+/* jshint esnext:true */
 /*
  *
  *  Weather extension for GNOME Shell
@@ -144,7 +145,7 @@ const WeatherMenuButton = new Lang.Class({
             text: _('...')
         });
 
-        if (St.TextDirection == undefined) {
+        if (St.TextDirection === undefined) {
             // Panel icon
             this._weatherIcon = new St.Icon({
                 icon_name: 'view-refresh' + this.icon_type(),
@@ -196,7 +197,7 @@ const WeatherMenuButton = new Lang.Class({
                 Main.panel._rightBox.insert_child_at_index(this.actor, 0);
                 break;
         }
-        if (Main.panel._menus == undefined)
+        if (Main.panel._menus === undefined)
             Main.panel.menuManager.addMenu(this.menu);
         else
             Main.panel._menus.addMenu(this.menu);
@@ -295,8 +296,8 @@ const WeatherMenuButton = new Lang.Class({
     },
 
     stop: function() {
-        if (_httpSession != undefined)
-            !_httpSession.abort();
+        if (_httpSession !== undefined)
+            _httpSession.abort();
 
         _httpSession = undefined;
 
@@ -721,7 +722,7 @@ const WeatherMenuButton = new Lang.Class({
         if (!cities[0])
             cities = [];
 
-        if (cities.length == 0) {
+        if (cities.length === 0) {
             this._cities = "2516479>Eivissa (CA)";
             this.updateCities();
             return;
@@ -734,7 +735,7 @@ const WeatherMenuButton = new Lang.Class({
                     type: 'like'
                 };
                 if (this._appid)
-                    params['APPID'] = this._appid;
+                    params.APPID = this._appid;
 
                 this.load_json_async(WEATHER_URL_CURRENT, params, Lang.bind(this, this._updateCitiesCallback));
                 return;
@@ -769,7 +770,7 @@ const WeatherMenuButton = new Lang.Class({
     },
 
     _onOpenStateChanged: function(menu, open) {
-        if (open && this._forecastScrollBox != undefined && this._forecastBox != undefined && this._currentWeather != undefined) {
+        if (open && this._forecastScrollBox !== undefined && this._forecastBox !== undefined && this._currentWeather !== undefined) {
             this._forecastScrollBox.set_width(this._currentWeather.get_width());
             this._forecastScrollBox.show();
             if (this._forecastBox.get_width() > this._currentWeather.get_width()) {
@@ -1142,7 +1143,7 @@ weather-storm.png = weather-storm-symbolic.svg
     },
 
     load_json_async: function(url, params, fun) {
-        if (_httpSession == undefined) {
+        if (_httpSession === undefined) {
             if (ExtensionUtils.versionCheck(['3.6'], Config.PACKAGE_VERSION)) {
                 // Soup session (see https://bugzilla.gnome.org/show_bug.cgi?id=661323#c64) (Simon Legner)
                 _httpSession = new Soup.SessionAsync();
@@ -1171,7 +1172,7 @@ weather-storm.png = weather-storm-symbolic.svg
     },
 
     parseWeatherCurrent: function() {
-        if (this.currentWeatherCache == undefined) {
+        if (this.currentWeatherCache === undefined) {
             this.refreshWeatherCurrent();
             return;
         }
@@ -1231,10 +1232,10 @@ weather-storm.png = weather-storm-symbolic.svg
 
         let iconname = this.get_weather_icon_safely(json.weather[0].id, now < sunrise || now > sunset);
 
-        if (this.lastBuildId == undefined)
+        if (this.lastBuildId === undefined)
             this.lastBuildId = 0;
 
-        if (this.lastBuildDate == undefined)
+        if (this.lastBuildDate === undefined)
             this.lastBuildDate = 0;
 
         if (this.lastBuildId != json.dt || !this.lastBuildDate) {
@@ -1398,7 +1399,7 @@ weather-storm.png = weather-storm-symbolic.svg
 
         if (!wind)
             this._currentWeatherWind.text = '\u2013';
-        else if (wind == 0 || !wind_direction)
+        else if (wind === 0 || !wind_direction)
             this._currentWeatherWind.text = parseFloat(wind).toLocaleString() + ' ' + wind_unit;
         else // i.e. wind > 0 && wind_direction
             this._currentWeatherWind.text = wind_direction + ' ' + parseFloat(wind).toLocaleString() + ' ' + wind_unit;
@@ -1418,7 +1419,7 @@ weather-storm.png = weather-storm-symbolic.svg
             units: 'metric'
         };
         if (this._appid)
-            params['APPID'] = this._appid;
+            params.APPID = this._appid;
 
         this.load_json_async(WEATHER_URL_CURRENT, params, function(json) {
             if (json && (Number(json.cod) == 200)) {
@@ -1454,7 +1455,7 @@ weather-storm.png = weather-storm-symbolic.svg
     },
 
     parseWeatherForecast: function() {
-        if (this.forecastWeatherCache == undefined) {
+        if (this.forecastWeatherCache === undefined) {
             this.refreshWeatherForecast();
             return;
         }
@@ -1466,7 +1467,7 @@ weather-storm.png = weather-storm-symbolic.svg
         for (let i = 0; i < this._days_forecast; i++) {
             let forecastUi = this._forecast[i];
             let forecastData = forecast[i];
-            if (forecastData == undefined)
+            if (forecastData === undefined)
                 continue;
 
             let t_low = forecastData.temp.min;
@@ -1553,7 +1554,7 @@ weather-storm.png = weather-storm-symbolic.svg
             cnt: '13'
         };
         if (this._appid)
-            params['APPID'] = this._appid;
+            params.APPID = this._appid;
 
         this.load_json_async(WEATHER_URL_FORECAST, params, function(json) {
             if (json && (Number(json.cod) == 200)) {
@@ -1586,12 +1587,12 @@ weather-storm.png = weather-storm-symbolic.svg
     },
 
     destroyCurrentWeather: function() {
-        if (this._currentWeather.get_child() != null)
+        if (this._currentWeather.get_child() !== null)
             this._currentWeather.get_child().destroy();
     },
 
     destroyFutureWeather: function() {
-        if (this._futureWeather.get_child() != null)
+        if (this._futureWeather.get_child() !== null)
             this._futureWeather.get_child().destroy();
     },
 
@@ -1722,7 +1723,7 @@ weather-storm.png = weather-storm-symbolic.svg
     },
 
     scrollForecastBy: function(delta) {
-        if (this._forecastScrollBox == undefined)
+        if (this._forecastScrollBox === undefined)
             return;
         this._forecastScrollBox.hscroll.adjustment.value += delta;
     },
diff --git a/src/prefs.js b/src/prefs.js
index 62df185..553d3f6 100644
--- a/src/prefs.js
+++ b/src/prefs.js
@@ -1,3 +1,4 @@
+/* jshint esnext:true */
 /*
  *
  *  Weather extension for GNOME Shell preferences
@@ -160,7 +161,7 @@ const WeatherPrefsWidget = new GObject.Class({
         this.Window.get_object("tree-toolbutton-remove").sensitive = Boolean(this.city.length);
 
         if (mCities != this.city) {
-            if (this.liststore != undefined)
+            if (this.liststore !== undefined)
                 this.liststore.clear();
 
             if (this.city.length > 0) {
@@ -290,7 +291,7 @@ const WeatherPrefsWidget = new GObject.Class({
     selectionChanged: function(select) {
         let a = select.get_selected_rows(this.liststore)[0][0];
 
-        if (a != undefined)
+        if (a !== undefined)
             if (this.actual_city != parseInt(a.to_string()))
                 this.actual_city = parseInt(a.to_string());
     },
@@ -349,7 +350,7 @@ const WeatherPrefsWidget = new GObject.Class({
                 id: id
             }, function() {
                 d.sensitive = 0;
-                if (arguments[0] == undefined)
+                if (arguments[0] === undefined)
                     return 0;
 
                 let city = arguments[0];
@@ -357,7 +358,7 @@ const WeatherPrefsWidget = new GObject.Class({
                 if (Number(city.cod) != 200)
                     return 0;
 
-                if (Number(city.count) == 0)
+                if (Number(city.count) === 0)
                     return 0;
 
                 d.sensitive = 1;
@@ -376,8 +377,8 @@ const WeatherPrefsWidget = new GObject.Class({
                 q: location
             };
             if (this.appid)
-                params['APPID'] = this.appid;
-            if (testLocation(location) == 0)
+                params.APPID = this.appid;
+            if (testLocation(location) === 0)
                 this.loadJsonAsync(WEATHER_URL_FIND, params, function() {
                     if (!arguments[0])
                         return 0;
@@ -441,7 +442,7 @@ const WeatherPrefsWidget = new GObject.Class({
                     type: 'accurate'
                 };
                 if (this.appid)
-                    params['APPID'] = this.appid;
+                    params.APPID = this.appid;
                 this.loadJsonAsync(WEATHER_URL_CURRENT, params, Lang.bind(this, function() {
                     if (!arguments[0])
                         return 0;
@@ -505,7 +506,7 @@ const WeatherPrefsWidget = new GObject.Class({
         dialog_area.pack_start(label, 0, 0, 0);
         dialog.connect("response", Lang.bind(this, function(w, response_id) {
             if (response_id) {
-                if (city.length == 0)
+                if (city.length === 0)
                     city = [];
 
                 if (city.length > 0 && typeof city != "object")
@@ -538,7 +539,7 @@ const WeatherPrefsWidget = new GObject.Class({
     },
 
     loadJsonAsync: function(url, params, fun, id) {
-        if (_httpSession == undefined) {
+        if (_httpSession === undefined) {
             if (ExtensionUtils.versionCheck(['3.6'], Config.PACKAGE_VERSION)) {
                 // Soup session (see https://bugzilla.gnome.org/show_bug.cgi?id=661323#c64) (Simon Legner)
                 _httpSession = new Soup.SessionAsync();
@@ -551,10 +552,10 @@ const WeatherPrefsWidget = new GObject.Class({
 
         let message = Soup.form_request_new_from_hash('GET', url, params);
 
-        if (this.asyncSession == undefined)
+        if (this.asyncSession === undefined)
             this.asyncSession = {};
 
-        if (this.asyncSession[id] != undefined && this.asyncSession[id]) {
+        if (this.asyncSession[id] !== undefined && this.asyncSession[id]) {
             _httpSession.abort();
             this.asyncSession[id] = 0;
         }