diff --git a/src/js/app.js b/src/js/app.js
index fc84cf4..654dc1d 100644
--- a/src/js/app.js
+++ b/src/js/app.js
@@ -31,12 +31,12 @@ const Minibus = require('minibus');
     }
   };
 
-  /*if ('serviceWorker' in navigator)
+  if ('serviceWorker' in navigator)
     navigator.serviceWorker
       .register('./service-worker.js')
       .then(function() {
         console.log('Service Worker Registered');
-      });*/
+      });
 
   app.createViews();
 
diff --git a/src/service-worker.js b/src/service-worker.js
index 2d06354..a7e87eb 100644
--- a/src/service-worker.js
+++ b/src/service-worker.js
@@ -12,13 +12,21 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-var dataCacheName = 'traintimesData-v1';
-var cacheName = 'traintimePWA-final-1';
-var filesToCache = [
+const dataCacheName = 'traintimesData-v1';
+const cacheName = 'traintimePWA-final-1';
+const filesToCache = [
   '/',
   '/index.html',
+  '/service-worker.js',
+  '/manifest.json',
+  '/browserconfig.xml',
+  '/css/common.css',
+  '/css/mui.custom.css',
+  '/fonts/fonts.css',
+  '/fonts/Roboto_Condensed-normal-400.woff',
+  '/fonts/Roboto_Slab-normal-400.woff',
   '/js/bundle.js',
-  '/css/common.css'
+  '/js/vendor.js'
 ];
 
 self.addEventListener('install', function(e) {
@@ -26,6 +34,7 @@ self.addEventListener('install', function(e) {
   e.waitUntil(
     caches.open(cacheName).then(function(cache) {
       console.log('[ServiceWorker] Caching app shell');
+      
       return cache.addAll(filesToCache);
     })
   );
@@ -38,11 +47,13 @@ self.addEventListener('activate', function(e) {
       return Promise.all(keyList.map(function(key) {
         if (key !== cacheName && key !== dataCacheName) {
           console.log('[ServiceWorker] Removing old cache', key);
+          
           return caches.delete(key);
         }
       }));
     })
   );
+
   /*
    * Fixes a corner case in which the app wasn't returning the latest data.
    * You can reproduce the corner case by commenting out the line below and
@@ -58,9 +69,10 @@ self.addEventListener('activate', function(e) {
 
 self.addEventListener('fetch', function(e) {
   console.log('[Service Worker] Fetch', e.request.url);
-  var dataUrl = '/getnexttraintimes?';
+  const dataUrl = '/getnexttraintimes?';
   if (e.request.url.indexOf(dataUrl) > -1) {
     console.log('!');
+
     /*
      * When the request URL contains dataUrl, the app is asking for fresh
      * weather data. In this case, the service worker always goes to the
@@ -70,13 +82,16 @@ self.addEventListener('fetch', function(e) {
      */
     e.respondWith(
       caches.open(dataCacheName).then(function(cache) {
-        return fetch(e.request).then(function(response){
+        return fetch(e.request).then(function(response) {
           cache.put(e.request.url, response.clone());
+          
           return response;
         });
       })
     );
-  } else {
+  }
+  else 
+
     /*
      * The app is asking for app shell files. In this scenario the app uses the
      * "Cache, falling back to the network" offline strategy:
@@ -87,5 +102,4 @@ self.addEventListener('fetch', function(e) {
         return response || fetch(e.request);
       })
     );
-  }
 });