diff --git a/server/package.json b/server/package.json
index a8e0932..1a6944a 100644
--- a/server/package.json
+++ b/server/package.json
@@ -3,6 +3,7 @@
   "version": "0.1.0",
   "description": "Server of Open Generals.IO",
   "main": "src/index.js",
+  "type": "module",
   "scripts": {
   },
   "repository": {
diff --git a/server/src/index.js b/server/src/index.mjs
similarity index 100%
rename from server/src/index.js
rename to server/src/index.mjs