diff --git a/browser/components/MarkdownPreview.js b/browser/components/MarkdownPreview.js
index 5cc4eca8..7a1f6815 100644
--- a/browser/components/MarkdownPreview.js
+++ b/browser/components/MarkdownPreview.js
@@ -170,10 +170,10 @@ export default class MarkdownPreview extends React.Component {
   }
 
   setCodeTheme (theme) {
-    const pathToCss = consts.THEMES.some((_theme) => _theme === theme)
-      ? `theme/${theme}.css`
-      : 'lib/codemirror.css'
-    this.getWindow().document.getElementById('codeTheme').href = `${appPath}/node_modules/codemirror/${pathToCss}`
+    theme = consts.THEMES.some((_theme) => _theme === theme)
+      ? theme
+      : 'default'
+    this.getWindow().document.getElementById('codeTheme').href = `${appPath}/node_modules/codemirror/theme/${theme}.css`
   }
 
   rewriteIframe () {
diff --git a/browser/lib/consts.js b/browser/lib/consts.js
index fe108fd1..253bc974 100644
--- a/browser/lib/consts.js
+++ b/browser/lib/consts.js
@@ -30,7 +30,7 @@ const consts = {
     'Dodger Blue',
     'Violet Eggplant'
   ],
-  THEMES: themes,
+  THEMES: ['default'].concat(themes)
 }
 
 module.exports = consts