diff --git a/browser/components/MarkdownPreview.js b/browser/components/MarkdownPreview.js
index 2b00fa94..c5fbc949 100644
--- a/browser/components/MarkdownPreview.js
+++ b/browser/components/MarkdownPreview.js
@@ -184,7 +184,7 @@ export default class MarkdownPreview extends React.Component {
   }
 
   setCodeTheme (theme) {
-    theme = consts.THEMES.some((_theme) => _theme === theme)
+    theme = consts.THEMES.some((_theme) => _theme === theme) && theme !== 'default'
       ? theme
       : 'elegant'
     this.getWindow().document.getElementById('codeTheme').href = `${appPath}/node_modules/codemirror/theme/${theme}.css`