diff --git a/browser/components/MarkdownPreview.js b/browser/components/MarkdownPreview.js
index fdc49f83..c1b7f01e 100755
--- a/browser/components/MarkdownPreview.js
+++ b/browser/components/MarkdownPreview.js
@@ -242,7 +242,7 @@ function getSourceLineNumberByElement(element) {
 }
 
 class MarkdownPreview extends React.Component {
-  constructor (props) {
+  constructor(props) {
     super(props)
 
     this.contextMenuHandler = e => this.handleContextMenu(e)