diff --git a/super-tiny-compiler-unannotated.js b/super-tiny-compiler-unannotated.js
index 6fb0a9c..af26cc9 100644
--- a/super-tiny-compiler-unannotated.js
+++ b/super-tiny-compiler-unannotated.js
@@ -46,7 +46,7 @@ function tokenizer(input) {
       continue;
     }
 
-    var LETTERS = /[a-zA-Z]/;
+    var LETTERS = /[a-z]i/;
     if (LETTERS.test(char)) {
       var value = '';