diff --git a/plugins/filters.js b/plugins/filters.js
index 414700f7..a6e759ed 100644
--- a/plugins/filters.js
+++ b/plugins/filters.js
@@ -61,7 +61,7 @@ export default ({ app, store }) => {
 
   Vue.filter('recurrentDetail', event => {
     const parent = event.parent
-    if (!parent.recurrent || parent.recurrent.frequency) return 'error!'
+    if (!parent.recurrent || !parent.recurrent.frequency) return 'error!'
     const { frequency, type } = parent.recurrent
     let recurrent
     if (frequency === '1w' || frequency === '2w') {