diff --git a/public/js/code_highlighter.js b/public/js/code_highlighter.js
index b959812..ac2ee26 100644
--- a/public/js/code_highlighter.js
+++ b/public/js/code_highlighter.js
@@ -24,6 +24,10 @@ const match = (m) => (peek, take) => {
   return true;
 }
 const match_identifier = (m) => (peek, take) => {
+  try {
+  if (peek(-1).match(/[0-9a-z_]/))
+    return false;
+  } catch {}
   if (match(m)(peek, take)) {
     if (peek(0).match(/[0-9a-z]/)) {
       take(-m.length);