diff --git a/src/api/build.ts b/src/api/build.ts
index ac563de..201e355 100644
--- a/src/api/build.ts
+++ b/src/api/build.ts
@@ -26,7 +26,7 @@ export async function build({
 	cwd,
 	src = 'src',
 	routes = 'src/routes',
-	output = '__sapper__',
+	output = 'src/node_modules/@sapper',
 	static: static_files = 'static',
 	dest = '__sapper__/build',
 
@@ -48,6 +48,9 @@ export async function build({
 		throw new Error(`Legacy builds are not supported for projects using webpack`);
 	}
 
+	rimraf.sync(path.join(output, '**/*'));
+	mkdirp.sync(output);
+
 	rimraf.sync(path.join(dest, '**/*'));
 	mkdirp.sync(`${dest}/client`);
 	copy_shimport(dest);
diff --git a/src/cli.ts b/src/cli.ts
index 085c981..161ab80 100755
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -29,7 +29,7 @@ prog.command('dev')
 	.option('--src', 'Source directory', 'src')
 	.option('--routes', 'Routes directory', 'src/routes')
 	.option('--static', 'Static files directory', 'static')
-	.option('--output', 'Sapper output directory', '__sapper__')
+	.option('--output', 'Sapper output directory', 'src/node_modules/@sapper')
 	.option('--build-dir', 'Development build directory', '__sapper__/dev')
 	.action(async (opts: {
 		port: number,
@@ -142,7 +142,7 @@ prog.command('build [dest]')
 	.option('--cwd', 'Current working directory', '.')
 	.option('--src', 'Source directory', 'src')
 	.option('--routes', 'Routes directory', 'src/routes')
-	.option('--output', 'Sapper output directory', '__sapper__')
+	.option('--output', 'Sapper output directory', 'src/node_modules/@sapper')
 	.example(`build custom-dir -p 4567`)
 	.action(async (dest = '__sapper__/build', opts: {
 		port: string,
@@ -188,7 +188,7 @@ prog.command('export [dest]')
 	.option('--src', 'Source directory', 'src')
 	.option('--routes', 'Routes directory', 'src/routes')
 	.option('--static', 'Static files directory', 'static')
-	.option('--output', 'Sapper output directory', '__sapper__')
+	.option('--output', 'Sapper output directory', 'src/node_modules/@sapper')
 	.option('--build-dir', 'Intermediate build directory', '__sapper__/build')
 	.action(async (dest = '__sapper__/export', opts: {
 		build: boolean,
diff --git a/test/apps/basics/src/client.js b/test/apps/basics/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/basics/src/client.js
+++ b/test/apps/basics/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/basics/src/server.js b/test/apps/basics/src/server.js
index 0e7741c..7f090b8 100644
--- a/test/apps/basics/src/server.js
+++ b/test/apps/basics/src/server.js
@@ -1,5 +1,5 @@
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/basics/src/service-worker.js b/test/apps/basics/src/service-worker.js
index 9d2ac9d..c80a8f4 100644
--- a/test/apps/basics/src/service-worker.js
+++ b/test/apps/basics/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
-// `shell` is an array of all the files generated by webpack,
-// `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+// `app.shell` is an array of all the files generated by webpack,
+// `app.files` is an array of everything in the `static` directory
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -52,7 +52,6 @@ self.addEventListener('fetch', event => {
 	// 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))) {
 		event.respondWith(caches.match('/index.html'));
 		return;
 	}
@@ -65,7 +64,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/credentials/src/client.js b/test/apps/credentials/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/credentials/src/client.js
+++ b/test/apps/credentials/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/credentials/src/server.js b/test/apps/credentials/src/server.js
index 2761f50..951243e 100644
--- a/test/apps/credentials/src/server.js
+++ b/test/apps/credentials/src/server.js
@@ -1,5 +1,5 @@
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/credentials/src/service-worker.js b/test/apps/credentials/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/credentials/src/service-worker.js
+++ b/test/apps/credentials/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/css/src/client.js b/test/apps/css/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/css/src/client.js
+++ b/test/apps/css/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/css/src/server.js b/test/apps/css/src/server.js
index 0e7741c..7f090b8 100644
--- a/test/apps/css/src/server.js
+++ b/test/apps/css/src/server.js
@@ -1,5 +1,5 @@
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/css/src/service-worker.js b/test/apps/css/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/css/src/service-worker.js
+++ b/test/apps/css/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/encoding/src/client.js b/test/apps/encoding/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/encoding/src/client.js
+++ b/test/apps/encoding/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/encoding/src/server.js b/test/apps/encoding/src/server.js
index 0e7741c..7f090b8 100644
--- a/test/apps/encoding/src/server.js
+++ b/test/apps/encoding/src/server.js
@@ -1,5 +1,5 @@
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/encoding/src/service-worker.js b/test/apps/encoding/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/encoding/src/service-worker.js
+++ b/test/apps/encoding/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/errors/src/client.js b/test/apps/errors/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/errors/src/client.js
+++ b/test/apps/errors/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/errors/src/server.js b/test/apps/errors/src/server.js
index 0e7741c..7f090b8 100644
--- a/test/apps/errors/src/server.js
+++ b/test/apps/errors/src/server.js
@@ -1,5 +1,5 @@
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/errors/src/service-worker.js b/test/apps/errors/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/errors/src/service-worker.js
+++ b/test/apps/errors/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/export/src/client.js b/test/apps/export/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/export/src/client.js
+++ b/test/apps/export/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/export/src/server.js b/test/apps/export/src/server.js
index d5a668b..2c6932d 100644
--- a/test/apps/export/src/server.js
+++ b/test/apps/export/src/server.js
@@ -1,6 +1,6 @@
 import sirv from 'sirv';
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT, NODE_ENV } = process.env;
 const dev = NODE_ENV === 'development';
diff --git a/test/apps/export/src/service-worker.js b/test/apps/export/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/export/src/service-worker.js
+++ b/test/apps/export/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/ignore/src/client.js b/test/apps/ignore/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/ignore/src/client.js
+++ b/test/apps/ignore/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/ignore/src/server.js b/test/apps/ignore/src/server.js
index f987e4a..4a66815 100644
--- a/test/apps/ignore/src/server.js
+++ b/test/apps/ignore/src/server.js
@@ -1,5 +1,5 @@
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/ignore/src/service-worker.js b/test/apps/ignore/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/ignore/src/service-worker.js
+++ b/test/apps/ignore/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/layout/src/client.js b/test/apps/layout/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/layout/src/client.js
+++ b/test/apps/layout/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/layout/src/server.js b/test/apps/layout/src/server.js
index 0e7741c..7f090b8 100644
--- a/test/apps/layout/src/server.js
+++ b/test/apps/layout/src/server.js
@@ -1,5 +1,5 @@
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/layout/src/service-worker.js b/test/apps/layout/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/layout/src/service-worker.js
+++ b/test/apps/layout/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/preloading/src/client.js b/test/apps/preloading/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/preloading/src/client.js
+++ b/test/apps/preloading/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/preloading/src/server.js b/test/apps/preloading/src/server.js
index 0e7741c..7f090b8 100644
--- a/test/apps/preloading/src/server.js
+++ b/test/apps/preloading/src/server.js
@@ -1,5 +1,5 @@
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/preloading/src/service-worker.js b/test/apps/preloading/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/preloading/src/service-worker.js
+++ b/test/apps/preloading/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/redirects/src/client.js b/test/apps/redirects/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/redirects/src/client.js
+++ b/test/apps/redirects/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/redirects/src/server.js b/test/apps/redirects/src/server.js
index 0e7741c..7f090b8 100644
--- a/test/apps/redirects/src/server.js
+++ b/test/apps/redirects/src/server.js
@@ -1,5 +1,5 @@
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/redirects/src/service-worker.js b/test/apps/redirects/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/redirects/src/service-worker.js
+++ b/test/apps/redirects/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/scroll/src/client.js b/test/apps/scroll/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/scroll/src/client.js
+++ b/test/apps/scroll/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/scroll/src/server.js b/test/apps/scroll/src/server.js
index 0e7741c..7f090b8 100644
--- a/test/apps/scroll/src/server.js
+++ b/test/apps/scroll/src/server.js
@@ -1,5 +1,5 @@
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/scroll/src/service-worker.js b/test/apps/scroll/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/scroll/src/service-worker.js
+++ b/test/apps/scroll/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/store/src/client.js b/test/apps/store/src/client.js
index df66471..eb6262c 100644
--- a/test/apps/store/src/client.js
+++ b/test/apps/store/src/client.js
@@ -1,5 +1,5 @@
 import { Store } from 'svelte/store.js';
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper'),
diff --git a/test/apps/store/src/server.js b/test/apps/store/src/server.js
index c40e690..843b06d 100644
--- a/test/apps/store/src/server.js
+++ b/test/apps/store/src/server.js
@@ -1,6 +1,6 @@
 import polka from 'polka';
 import { Store } from 'svelte/store.js';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT } = process.env;
 
diff --git a/test/apps/store/src/service-worker.js b/test/apps/store/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/store/src/service-worker.js
+++ b/test/apps/store/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);
diff --git a/test/apps/with-basepath/src/client.js b/test/apps/with-basepath/src/client.js
index 0865a4a..5fd4ce8 100644
--- a/test/apps/with-basepath/src/client.js
+++ b/test/apps/with-basepath/src/client.js
@@ -1,4 +1,4 @@
-import * as sapper from '../__sapper__/client.js';
+import * as sapper from '@sapper/client';
 
 window.start = () => sapper.start({
 	target: document.querySelector('#sapper')
diff --git a/test/apps/with-basepath/src/server.js b/test/apps/with-basepath/src/server.js
index b187dad..22da3e9 100644
--- a/test/apps/with-basepath/src/server.js
+++ b/test/apps/with-basepath/src/server.js
@@ -1,6 +1,6 @@
 import sirv from 'sirv';
 import polka from 'polka';
-import * as sapper from '../__sapper__/server.js';
+import * as sapper from '@sapper/server';
 
 const { PORT, NODE_ENV } = process.env;
 const dev = NODE_ENV === 'development';
diff --git a/test/apps/with-basepath/src/service-worker.js b/test/apps/with-basepath/src/service-worker.js
index 9d2ac9d..8adb97a 100644
--- a/test/apps/with-basepath/src/service-worker.js
+++ b/test/apps/with-basepath/src/service-worker.js
@@ -1,10 +1,10 @@
-import { timestamp, files, shell, routes } from '../__sapper__/service-worker.js';
+import * as sapper from '@sapper/service-worker';
 
-const ASSETS = `cache${timestamp}`;
+const ASSETS = `cache${sapper.timestamp}`;
 
 // `shell` is an array of all the files generated by webpack,
 // `files` is an array of everything in the `static` directory
-const to_cache = shell.concat(ASSETS);
+const to_cache = sapper.shell.concat(sapper.files);
 const cached = new Set(to_cache);
 
 self.addEventListener('install', event => {
@@ -65,7 +65,7 @@ self.addEventListener('fetch', event => {
 	// might prefer a cache-first approach to a network-first one.)
 	event.respondWith(
 		caches
-			.open(`offline${timestamp}`)
+			.open(`offline${sapper.timestamp}`)
 			.then(async cache => {
 				try {
 					const response = await fetch(event.request);