diff --git a/config/site_settings.yml b/config/site_settings.yml
index a50d59f2c9f..09b886ee5fb 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -819,6 +819,7 @@ posting:
       zh_TW: 120
   topic_excerpt_maxlength:
     default: 220
+    max: 999
     locale_default:
       ja: 120
       zh_CN: 120