diff --git a/sw.js b/sw.js
index f5195bd..57fbc51 100644
--- a/sw.js
+++ b/sw.js
@@ -14,7 +14,7 @@ self.addEventListener('activate', event => {
             Promise.all(
                 keys.filter(k => k !== CACHE_NAME).map(k => caches.delete(k))
             )
-        )
+        ).catch(err => console.warn('[SW] activate error', err))
     );
     self.clients.claim();
 });