diff --git a/learn.php b/learn.php
index 445b650..678868c 100644
--- a/learn.php
+++ b/learn.php
@@ -119,7 +119,9 @@ document.getElementById('answer').addEventListener('keydown', function (e) {
         check();
     }
 });
-
+if ('serviceWorker' in navigator) {
+    navigator.serviceWorker.register('/service-worker.js');
+}
 </script>
 
 </body>