diff --git a/browser/lib/markdown.js b/browser/lib/markdown.js
index 0ea15ba9..df429b19 100644
--- a/browser/lib/markdown.js
+++ b/browser/lib/markdown.js
@@ -181,7 +181,7 @@ class Markdown {
     })
 
     const deflate = require('markdown-it-plantuml/lib/deflate')
-    this.md.use(require('markdown-it-plantuml'), '', {
+    this.md.use(require('markdown-it-plantuml'), {
       generateSource: function (umlCode) {
         const stripTrailingSlash = (url) => url.endsWith('/') ? url.slice(0, -1) : url
         const serverAddress = stripTrailingSlash(config.preview.plantUMLServerAddress) + '/svg'