diff --git a/lib/micropython-microbit-v2 b/lib/micropython-microbit-v2
index 8aaa36b8..17aaa115 160000
--- a/lib/micropython-microbit-v2
+++ b/lib/micropython-microbit-v2
@@ -1 +1 @@
-Subproject commit 8aaa36b8d50211f5902d50e050632a88358d369f
+Subproject commit 17aaa115ad4ad285377b2eb210f37b0e94f61aa9
diff --git a/src/simulator.ts b/src/simulator.ts
index 7b129130..74107222 100644
--- a/src/simulator.ts
+++ b/src/simulator.ts
@@ -47,13 +47,10 @@ if ("serviceWorker" in navigator) {
   if (flags.sw) {
     initServiceWorker();
   } else {
-    navigator.serviceWorker.getRegistrations().then((registrations) => {
-      if (registrations.length > 0) {
-        // We should only have one service worker to unregister.
-        registrations[0].unregister().then(() => {
-          window.location.reload();
-        });
-      }
+    navigator.serviceWorker.getRegistration().then((registration) => {
+      registration?.unregister().then(() => {
+        window.location.reload();
+      });
     });
   }
 }