diff --git a/sw.js b/sw.js
index b639469..a1057f7 100644
--- a/sw.js
+++ b/sw.js
@@ -1,10 +1,18 @@
-const CACHE_NAME = 'states-tracker-v1';
+const CACHE_NAME = 'states-tracker-__COMMIT_HASH__';
 const ASSETS = ['/', '/index.html', '/styles.css', '/app.js', '/manifest.json', '/IN.svg'];
 
 self.addEventListener('install', e => {
   e.waitUntil(caches.open(CACHE_NAME).then(cache => cache.addAll(ASSETS)));
 });
 
+self.addEventListener('activate', e => {
+  e.waitUntil(
+    caches.keys().then(keys =>
+      Promise.all(keys.filter(key => key !== CACHE_NAME).map(key => caches.delete(key)))
+    )
+  );
+});
+
 self.addEventListener('fetch', e => {
   e.respondWith(
     caches.match(e.request).then(cached => cached || fetch(e.request))
diff --git a/vercel.json b/vercel.json
new file mode 100644
index 0000000..4782706
--- /dev/null
+++ b/vercel.json
@@ -0,0 +1,4 @@
+{
+  "buildCommand": "bash -c \"sed -i 's/__COMMIT_HASH__/'${VERCEL_GIT_COMMIT_SHA:0:7}'/g' sw.js\"",
+  "outputDirectory": "."
+}