diff --git a/lib/jison.js b/lib/jison.js
index 3b01410d0..f8e883068 100755
--- a/lib/jison.js
+++ b/lib/jison.js
@@ -1422,7 +1422,7 @@ parser.parse = function parse (input) {
     }
 
 _token_stack:
-    function lex() {
+    var lex = function () {
         var token;
         token = lexer.lex() || EOF;
         // if token isn't its numeric value, convert