diff --git a/lib/index.iife.js b/lib/index.iife.js
index 76c8f0a..826254e 100644
--- a/lib/index.iife.js
+++ b/lib/index.iife.js
@@ -18,6 +18,7 @@ var VueDemi = (function (VueDemi, Vue, VueCompositionAPI) {
     VueDemi.Vue = Vue
     VueDemi.Vue2 = Vue
     VueDemi.version = Vue.version
+    VueDemi.warn = Vue.util.warn
     function createApp(rootComponent, rootProps) {
       var vm
       var provide = {}