diff --git a/app/assets/javascripts/discourse/widgets/post-edits-indicator.js.es6 b/app/assets/javascripts/discourse/widgets/post-edits-indicator.js.es6
index bffad584673..39ecedc81a6 100644
--- a/app/assets/javascripts/discourse/widgets/post-edits-indicator.js.es6
+++ b/app/assets/javascripts/discourse/widgets/post-edits-indicator.js.es6
@@ -41,7 +41,7 @@ export default createWidget("post-edits-indicator", {
 
     if (attrs.wiki) {
       icon = "pencil-square-o";
-      className = `${className} wiki`;
+      className = `${className || ''} wiki`.trim();
 
       if (attrs.version > 1) {
         title = `${I18n.t("post.last_edited_on")} ${date}`;