diff --git a/package.json b/package.json
index 8a38ecf343..3df35687d4 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
     "build:js": "tsc --module es6 --incremental",
     "bundle:js": "rollup -c -m dev",
     "bundle:xml": "node tools/bundle_xml/main.js",
-    "build": "npm-run-all build:js bundle:js 'bundle:xml -- --outDir build'",
+    "build": "npm-run-all build:js bundle:js \"bundle:xml -- --outDir build\"",
     "doc": "typedoc",
     "precommit": "npm run prettier && npm run doc",
     "test": "jest",
diff --git a/tools/bundle_xml/main.js b/tools/bundle_xml/main.js
index 7fa3087a0b..88a2a18fa8 100644
--- a/tools/bundle_xml/main.js
+++ b/tools/bundle_xml/main.js
@@ -1,6 +1,8 @@
 const bundle = require("./bundle_xml_templates");
 
-const outDirAgIndex = process.argv.findIndex((arg) => arg === "--outDir") + 1;
-const outDir = process.argv[outDirAgIndex] || "dist";
+const DEFAULT_DIR = "dist";
 
-bundle.writeOwlTemplateBundleToFile(outDir);
+const outDirFlagIndex = process.argv.findIndex((arg) => arg === "--outDir");
+const outDir = outDirFlagIndex !== -1 ? process.argv[outDirFlagIndex + 1] : DEFAULT_DIR;
+
+bundle.writeOwlTemplateBundleToFile(outDir || DEFAULT_DIR);