diff --git a/.gitignore b/.gitignore
index af19598..3190d8b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,4 +3,5 @@ __merged.js
 *~
 *.swp
 node_modules
-dist/
\ No newline at end of file
+dist/
+src/system/parser.generated.js
diff --git a/package.json b/package.json
index 912f1fe..2dffc31 100644
--- a/package.json
+++ b/package.json
@@ -13,6 +13,7 @@
     "build": "webpack",
     "build:types": "tsc --emitDeclarationOnly",
     "build:js": "babel src --out-dir lib --extensions \".ts,.tsx\" --source-maps inline",
+    "build:grammar": "peggy --format commonjs -o src/system/parser.generated.js grammar.peg",
     "test": "mocha -r ts-node/register test/interpreter.js"
   },
   "repository": {