diff --git a/build.js b/build.js
index 447a53a..f04e65d 100644
--- a/build.js
+++ b/build.js
@@ -3,7 +3,7 @@ import esbuild from "esbuild";
 esbuild.buildSync({
   entryPoints: ["src/index.ts"],
   outfile: "dist/index.js",
-  format: "esm",
+  format: "iife",
   bundle: true,
   legalComments: "external",
   //  minify: true