diff --git a/core/README.md b/core/README.md
index 5c012acc..53b20dbe 100644
--- a/core/README.md
+++ b/core/README.md
@@ -39,10 +39,11 @@ https://uiwjs.github.io/react-textarea-code-editor/
 [![Open in Github gh-pages](https://img.shields.io/badge/Open%20In-Github%20gh--pages-blue?logo=github)](https://uiwjs.github.io/react-textarea-code-editor/)
 
 ```jsx
+import React, { useState } from "react";
 import CodeEditor from '@uiw/react-textarea-code-editor';
 
-function App() {
-  const [code, setCode] = React.useState(
+export default function App() {
+  const [code, setCode] = useState(
     `function add(a, b) {\n  return a + b;\n}`
   );
   return (
@@ -53,7 +54,6 @@ function App() {
       onChange={(evn) => setCode(evn.target.value)}
       padding={15}
       style={{
-        fontSize: 12,
         backgroundColor: "#f5f5f5",
         fontFamily: 'ui-monospace,SFMono-Regular,SF Mono,Consolas,Liberation Mono,Menlo,monospace',
       }}
diff --git a/core/src/utils.ts b/core/src/utils.ts
index 63bd7fce..e6286017 100644
--- a/core/src/utils.ts
+++ b/core/src/utils.ts
@@ -1,8 +1,11 @@
-import { PluggableList } from 'unified';
+import { PluggableList, Pluggable } from 'unified';
 import { rehype } from 'rehype';
 import rehypePrism from 'rehype-prism-plus';
 
-export const processHtml = (html: string, plugins: PluggableList = [[rehypePrism, { ignoreMissing: true }]]) => {
+export const processHtml = (
+  html: string,
+  plugins: PluggableList = [[rehypePrism, { ignoreMissing: true }]] as Pluggable[],
+) => {
   return rehype()
     .data('settings', { fragment: true })
     .use([...plugins])