diff --git a/regexp-lexer.js b/regexp-lexer.js
index e0b38e7..c31aef7 100644
--- a/regexp-lexer.js
+++ b/regexp-lexer.js
@@ -1625,7 +1625,7 @@ function buildActions(dict, tokens, opts) {
     return {
         caseHelperInclude: '{\n' + caseHelper.join(',') + '\n}',
 
-        actions: 'function lexer__performAction(yy, yy_, $avoiding_name_collisions, YY_START) {\n' + fun + '\n}',
+        actions: expandParseArguments('function lexer__performAction(yy, yy_, $avoiding_name_collisions, YY_START, parseParams) {\n', opts) + fun + '\n}',
 
         rules: gen.rules,
         macros: gen.macros                   // propagate these for debugging/diagnostic purposes