diff --git a/.gitignore b/.gitignore
index f0db5c7..f75a141 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,3 @@
 node_modules/
-dist/main.js
+dist/*.js
 src/
diff --git a/build.sh b/build.sh
index 7b4555e..5b3c346 100755
--- a/build.sh
+++ b/build.sh
@@ -5,4 +5,4 @@ if [ ! -e ./src ]; then
 fi
 
 npx tsc &&
-npx webpack
+npx webpack --config webpack.config.js
diff --git a/ts/serviceWorker.ts b/ts/serviceWorker.ts
new file mode 100644
index 0000000..208bb94
--- /dev/null
+++ b/ts/serviceWorker.ts
@@ -0,0 +1,9 @@
+/// <reference lib="WebWorker" />
+
+// export empty type because of tsc --isolatedModules flag
+export type {};
+declare const self: ServiceWorkerGlobalScope;
+
+self.addEventListener('sync', (e: any) => {
+  console.log(e);
+});
\ No newline at end of file
diff --git a/tsconfig.json b/tsconfig.json
index 3b2a1b6..1e49f55 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,6 +1,8 @@
 {
   "compilerOptions": {
-    "target": "ES2022",
+    "target": "es5",
+    "lib": [ "es2022", "webworker", "dom" ],
+    "skipLibCheck": true,
     "module": "preserve",
     "moduleResolution": "bundler",
     "noImplicitAny": true,
diff --git a/webpack.config.js b/webpack.config.js
new file mode 100644
index 0000000..0e13b0f
--- /dev/null
+++ b/webpack.config.js
@@ -0,0 +1,9 @@
+const path = require('path');
+
+module.exports = {
+  context: path.resolve(__dirname, 'src'),
+  entry: {
+    main: './index.js',
+    serviceWorker: './serviceWorker.js'
+  }
+}
\ No newline at end of file