diff --git a/demo/zmodemjs b/demo/zmodemjs
index 5b37c522..cea252d1 160000
--- a/demo/zmodemjs
+++ b/demo/zmodemjs
@@ -1 +1 @@
-Subproject commit 5b37c522c0fc989d257dffd3279f33902f148ab6
+Subproject commit cea252d19bc64333254de8fb844b4b634df5b96e
diff --git a/package.json b/package.json
index dc1e47ae..eda89128 100644
--- a/package.json
+++ b/package.json
@@ -75,7 +75,7 @@
     "lint": "tslint src/*.ts src/**/*.ts",
     "test": "gulp test",
     "build:docs": "jsdoc -c jsdoc.json",
-    "build": "gulp build",
+    "build": "gulp build; cd demo/zmodemjs; npm install",
     "prepublish": "npm run build",
     "coveralls": "gulp coveralls"
   }