diff --git a/packages/mdx/mdx-ast-to-mdx-hast.js b/packages/mdx/mdx-ast-to-mdx-hast.js
index c7c5b28ea..2b0e8adbb 100644
--- a/packages/mdx/mdx-ast-to-mdx-hast.js
+++ b/packages/mdx/mdx-ast-to-mdx-hast.js
@@ -30,11 +30,11 @@ module.exports = function mdxAstToMdxHast() {
           props.className = ['language-' + lang]
         }
 
-        props.metaString = node.lang && node.lang.replace(langRegex, '').trim()
+        const metaString = node.lang && node.lang.replace(langRegex, '').trim()
 
         const meta =
-          props.metaString &&
-          props.metaString.split(' ').reduce((acc, cur) => {
+          metaString &&
+          metaString.split(' ').reduce((acc, cur) => {
             if (cur.split('=').length > 1) {
               const t = cur.split('=')
               acc[t[0]] = t[1]