diff --git a/packages/cra-template-typescript/template/src/serviceWorker.ts b/packages/cra-template-typescript/template/src/serviceWorker.ts
index b09523f155e..4d12c1ad7a2 100644
--- a/packages/cra-template-typescript/template/src/serviceWorker.ts
+++ b/packages/cra-template-typescript/template/src/serviceWorker.ts
@@ -29,7 +29,7 @@ export function register(config?: Config) {
   if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
     // The URL constructor is available in all browsers that support SW.
     const publicUrl = new URL(
-      process.env.PUBLIC_URL,
+      process.env.PUBLIC_URL as string,
       window.location.href
     );
     if (publicUrl.origin !== window.location.origin) {