diff --git a/packages/ui-default/pages/contest_balloon.page.tsx b/packages/ui-default/pages/contest_balloon.page.tsx
index bae997895..b876d5812 100644
--- a/packages/ui-default/pages/contest_balloon.page.tsx
+++ b/packages/ui-default/pages/contest_balloon.page.tsx
@@ -65,11 +65,8 @@ function Balloon({ tdoc, val }) {
 }
 
 async function handleSetColor(tdoc) {
-  let val = tdoc.balloon;
-  if (!val) {
-    val = {};
-    for (const pid of tdoc.pids) val[+pid] = { color: '#ffffff', name: '' };
-  }
+  const val = tdoc.balloon || {};
+  for (const pid of tdoc.pids) val[+pid] ||= { color: '#ffffff', name: '' };
   Notification.info(i18n('Loading...'));
   const action = await new ActionDialog({
     $body: tpl(<>