diff --git a/lib/parser.js b/lib/parser.js
index a8bd71b2..8212476d 100644
--- a/lib/parser.js
+++ b/lib/parser.js
@@ -1,4 +1,4 @@
-// @generated by Peggy 4.0.3.
+// @generated by Peggy 4.1.0-pre.0.
 //
 // https://peggyjs.org/
 
diff --git a/lib/version.js b/lib/version.js
index 75483daa..e30a0bcb 100644
--- a/lib/version.js
+++ b/lib/version.js
@@ -1,6 +1,6 @@
-// Generated by package-extract v2.2.0
+// Generated by package-extract v2.3.0
 // Do not modify by hand.
 
 "use strict";
 
-exports.version = "4.0.3";
+exports.version = "4.1.0-pre.0";
diff --git a/package.json b/package.json
index 009b9bcc..012cc6bf 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "peggy",
-  "version": "4.0.3",
+  "version": "4.1.0-pre.0",
   "description": "Parser generator for JavaScript",
   "keywords": [
     "grammar",