diff --git a/docs/index.bs b/docs/index.bs
index e6ec5a19..2c0223df 100644
--- a/docs/index.bs
+++ b/docs/index.bs
@@ -713,7 +713,7 @@ spec: storage; urlPrefix: https://storage.spec.whatwg.org/
         readonly attribute ServiceWorker? controller;
         readonly attribute Promise<ServiceWorkerRegistration> ready;
 
-        [NewObject] Promise<ServiceWorkerRegistration> register(USVString scriptURL, optional RegistrationOptions options = {});
+        [NewObject] Promise<ServiceWorkerRegistration> register(ScriptURLString scriptURL, optional RegistrationOptions options = {});
 
         [NewObject] Promise<(ServiceWorkerRegistration or undefined)> getRegistration(optional USVString clientURL = "");
         [NewObject] Promise<FrozenArray<ServiceWorkerRegistration>> getRegistrations();