diff --git a/repl/src/CodeMirror.tsx b/repl/src/CodeMirror.tsx
index faef177e..0d81a341 100644
--- a/repl/src/CodeMirror.tsx
+++ b/repl/src/CodeMirror.tsx
@@ -5,11 +5,12 @@ import 'codemirror/mode/pegjs/pegjs.js';
 import 'codemirror/theme/material.css';
 import 'codemirror/lib/codemirror.css';
 
-export default function CodeMirror({ value, onChange, options }: any) {
+export default function CodeMirror({ value, onChange, options, editorDidMount }: any) {
   options = options || {
     mode: 'javascript',
     theme: 'material',
     lineNumbers: true,
+    styleSelectedText: true,
   };
-  return <CodeMirror2 value={value} options={options} onBeforeChange={onChange} />;
+  return <CodeMirror2 value={value} options={options} onBeforeChange={onChange} editorDidMount={editorDidMount} />;
 }