diff --git a/extensions/flags/js/src/forum/addFlagControl.js b/extensions/flags/js/src/forum/addFlagControl.js
index 43cc59e33..c908ec294 100644
--- a/extensions/flags/js/src/forum/addFlagControl.js
+++ b/extensions/flags/js/src/forum/addFlagControl.js
@@ -10,7 +10,7 @@ export default function() {
     if (post.isHidden() || post.contentType() !== 'comment' || !post.canFlag()) return;
 
     items.add('flag',
-      <Button icon="fas fa-flag" onclick={() => app.modal.show(new FlagPostModal({post}))}>{app.translator.trans('flarum-flags.forum.post_controls.flag_button')}</Button>
+      <Button icon="fas fa-flag" onclick={() => app.modal.show(FlagPostModal, {post})}>{app.translator.trans('flarum-flags.forum.post_controls.flag_button')}</Button>
     );
   });
 }