diff --git a/lib/ace/mode/javascript_highlight_rules.js b/lib/ace/mode/javascript_highlight_rules.js
index ad3efba8..c45186c5 100644
--- a/lib/ace/mode/javascript_highlight_rules.js
+++ b/lib/ace/mode/javascript_highlight_rules.js
@@ -93,11 +93,7 @@ var JavaScriptHighlightRules = function() {
     );
 
     // TODO: Unicode escape sequences
-    var identifierRe = "[" + unicode.packages.L + "\\$_]["
-        + unicode.packages.L
-        + unicode.packages.Mn + unicode.packages.Mc
-        + unicode.packages.Nd
-        + unicode.packages.Pc + "\\$_]*\\b";
+    var identifierRe = "[a-zA-Z\\$_\u00a1-\uffff][a-zA-Z\d\\$_\u00a1-\uffff]*\\b";
 
     var escapedRe = "\\\\(?:x[0-9a-fA-F]{2}|" + // hex
         "u[0-9a-fA-F]{4}|" + // unicode