diff --git a/src/js/sr2ini.js b/src/js/sr2ini.js
index 8569445..5fb7178 100644
--- a/src/js/sr2ini.js
+++ b/src/js/sr2ini.js
@@ -1,7 +1,7 @@
 // Register Service Worker
 if ("serviceWorker" in navigator) {
 	navigator.serviceWorker.register(
-		new URL("service-worker.js", import.meta.url), { type: "module" }
+		new URL("./service-worker.js"), { type: "module" }
 	).then( (registration) => {
 		console.log('ServiceWorker registration successful with scope: ', registration.scope);
 	}, (err) => {
@@ -74,6 +74,9 @@ const PHYSICAL_BADGE_HTML = '<sub><span class="badge bg-danger position-absolute
 
 // roll for initiative with the given reaction and number of ini dice  
 function rollForInitiative(dice, rea) {
+	if (isNaN(parseInt(dice)) || isNaN(parseInt(rea))) {
+		return 0;
+	}
 	let diceRolls = Array.from({ length: parseInt(dice) }, () => Math.ceil(Math.random() * 6));
 	return diceRolls.reduce((a, b) => a + b, 0) + parseInt(rea);
 }