diff --git a/package-lock.json b/package-lock.json
index 3cd23daf..717e9437 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -8102,7 +8102,7 @@
       }
     },
     "sapper": {
-      "version": "github:nolanlawson/sapper#701bc3455a9387d76f8047e7152c8295c9516788",
+      "version": "github:nolanlawson/sapper#2b21a7cfefaa9305354ce0ce0a51a83e9fe645a6",
       "requires": {
         "chalk": "2.3.2",
         "chokidar": "1.7.0",
@@ -8131,13 +8131,14 @@
           }
         },
         "ajv": {
-          "version": "6.3.0",
-          "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.3.0.tgz",
-          "integrity": "sha1-FlCkERTvAFdMrBC4Ay2PTBSBLac=",
+          "version": "6.4.0",
+          "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.4.0.tgz",
+          "integrity": "sha1-06/3jpJ3VJdx2vAWTP9ISCt1T8Y=",
           "requires": {
             "fast-deep-equal": "1.0.0",
             "fast-json-stable-stringify": "2.0.0",
-            "json-schema-traverse": "0.3.1"
+            "json-schema-traverse": "0.3.1",
+            "uri-js": "3.0.2"
           }
         },
         "ansi-styles": {
@@ -8336,7 +8337,7 @@
           "requires": {
             "acorn": "5.3.0",
             "acorn-dynamic-import": "2.0.2",
-            "ajv": "6.3.0",
+            "ajv": "6.4.0",
             "ajv-keywords": "3.1.0",
             "async": "2.6.0",
             "enhanced-resolve": "3.4.1",
@@ -10230,6 +10231,21 @@
       "resolved": "https://registry.npmjs.org/upath/-/upath-1.0.4.tgz",
       "integrity": "sha512-d4SJySNBXDaQp+DPrziv3xGS6w3d2Xt69FijJr86zMPBy23JEloMCEOUBBzuN7xCtjLCnmB9tI/z7SBCahHBOw=="
     },
+    "uri-js": {
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/uri-js/-/uri-js-3.0.2.tgz",
+      "integrity": "sha1-+QuFhQf4HepNz7s8TD2/orVX+qo=",
+      "requires": {
+        "punycode": "2.1.0"
+      },
+      "dependencies": {
+        "punycode": {
+          "version": "2.1.0",
+          "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.1.0.tgz",
+          "integrity": "sha1-X4Y+3Im5bbCQdLrXlHvwkFbKTn0="
+        }
+      }
+    },
     "urix": {
       "version": "0.1.0",
       "resolved": "https://registry.npmjs.org/urix/-/urix-0.1.0.tgz",
diff --git a/server.js b/server.js
index 534ed12e..425759d9 100644
--- a/server.js
+++ b/server.js
@@ -17,7 +17,7 @@ app.use(compression({ threshold: 0 }))
 
 app.use(serveStatic('assets', {
   setHeaders: (res) => {
-    res.setHeader('Cache-Control', 'public,max-age=14400')
+    res.setHeader('Cache-Control', 'public,max-age=600')
   }
 }))
 
diff --git a/templates/service-worker.js b/templates/service-worker.js
index bbe0d6d4..f806331f 100644
--- a/templates/service-worker.js
+++ b/templates/service-worker.js
@@ -1,13 +1,19 @@
 const timestamp = '__timestamp__'
-const ASSETS = `cache${timestamp}`
+const ASSETS = `assets_${timestamp}`
+const ON_DEMAND = `ondemand_${timestamp}`
 
-// `shell` is an array of all the files generated by webpack,
 // `assets` is an array of everything in the `assets` directory
-const assets = __assets__.map(file => file.startsWith('/') ? file : `/${file}`)
-const toCache = __shell__.concat(assets)
-  .filter(filename => !filename.endsWith('.map'))
+const assets = __assets__
+  .map(file => file.startsWith('/') ? file : `/${file}`)
   .filter(filename => !filename.startsWith('/apple-icon'))
-const cached = new Set(toCache)
+
+// `shell` is an array of all the files generated by webpack
+// also contains '/index.html' for some reason
+const resources = __shell__
+  .filter(filename => !filename.endsWith('.map'))
+
+const toCache = [].concat(assets).concat(resources)
+const cacheSet = new Set(toCache)
 
 // `routes` is an array of `{ pattern: RegExp }` objects that
 // match the pages in your app
@@ -24,17 +30,19 @@ self.addEventListener('install', event => {
 self.addEventListener('activate', event => {
   event.waitUntil((async () => {
     let keys = await caches.keys()
-    // delete old caches
+
+    // delete old asset/ondemand caches
     for (let key of keys) {
-      if (key !== ASSETS) {
+      if (key !== ASSETS && key !== ON_DEMAND) {
         await caches.delete(key)
       }
     }
+
     await self.clients.claim()
   })())
 })
 
-const CACHE_FIRST = [
+const ON_DEMAND_PATHS = [
   '/system/accounts/avatars'
 ]
 
@@ -48,26 +56,24 @@ self.addEventListener('fetch', event => {
   }
 
   event.respondWith((async () => {
-    // always serve assets and webpack-generated files from cache
-    if (url.origin === self.origin && cached.has(url.pathname)) {
-      let cache = await caches.open(ASSETS)
-      return cache.match(req)
+    let sameOrigin = url.origin === self.origin
+
+    // always serve webpack-generated resources and
+    // assets from the cache
+    if (sameOrigin && cacheSet.has(url.pathname)) {
+      return caches.match(req)
     }
 
-    // for pages, you might want to serve a shell `index.html` file,
-    // which Sapper has generated for you. It's not right for every
-    // app, but if it's right for yours then uncomment this section
-
-    if (url.origin === self.origin &&
-        routes.find(route => route.pattern.test(url.pathname))) {
-      let cache = await caches.open(ASSETS)
-      return cache.match('/index.html')
+    // for routes, serve the /index.html file from the most recent
+    // assets cache
+    if (sameOrigin && routes.find(route => route.pattern.test(url.pathname))) {
+      return caches.match('/index.html')
     }
 
     // For these GET requests, go cache-first
     if (req.method === 'GET' &&
-        CACHE_FIRST.some(pattern => url.pathname.startsWith(pattern))) {
-      let cache = await caches.open(`offline${timestamp}`)
+        ON_DEMAND_PATHS.some(pattern => url.pathname.startsWith(pattern))) {
+      let cache = await caches.open(ON_DEMAND)
       let response = await cache.match(req)
       if (response) {
         // update asynchronously