diff --git a/vendor/prism-patches/prism-gleam.js b/vendor/prism-patches/prism-gleam.js
index 1eb53bd..aab66f7 100644
--- a/vendor/prism-patches/prism-gleam.js
+++ b/vendor/prism-patches/prism-gleam.js
@@ -7,7 +7,7 @@ Prism.languages.gleam = {
     pattern: /\/\/.*/,
     greedy: true,
   },
-  function: /(?<=fn )([a-z_][a-zA-Z0-9_]+)(?=\()/,
+  function: /(?<=fn )([a-z_][a-z0-9_]+)(?=\()/,
   keyword:
     /\b(use|case|if|external|fn|import|let|assert|try|pub|type|opaque|const|todo|as)\b/,
   operator: {