diff --git a/astro.config.mjs b/astro.config.mjs
index 45907ac..0e0bc91 100644
--- a/astro.config.mjs
+++ b/astro.config.mjs
@@ -28,7 +28,6 @@ export default defineConfig({
         waiting: () => console.log('>>> waiting...'),
         active: () => console.log('>>> active...'),
         error: (error) => console.error('>>> error', error),
-        unsupported: () => console.log('>>> service worker unsupported'),
         afterRegistration: async () => {
             const sw = await navigator.serviceWorker.getRegistration();
             console.log('>>> registrered', sw)
diff --git a/index.js b/index.js
index 8c63dd1..598828e 100644
--- a/index.js
+++ b/index.js
@@ -1,3 +1,4 @@
+// @ts-check
 /**
  * @license MIT <https://opensource.org/licenses/MIT>
  * @author Ayo Ayco <https://ayo.ayco.io>
@@ -50,12 +51,12 @@ export default function serviceWorker(options) {
     } = options || {};
 
     const {
-        installing: installingFn,
-        waiting: waitingFn,
-        active: activeFn,
-        error: errorFn,
-        unsupported: unsupportedFn,
-        afterRegistration: afterRegistrationFn,
+        installing: installingFn = () => {},
+        waiting: waitingFn = () => {},
+        active: activeFn = () => {},
+        error: errorFn = () => {},
+        unsupported: unsupportedFn = () => {},
+        afterRegistration: afterRegistrationFn = () => {},
     } = registrationHooks;
 
     /**