diff --git a/package.json b/package.json
index 324d4e8..730048f 100644
--- a/package.json
+++ b/package.json
@@ -40,7 +40,7 @@
     "browserify": "^13.0.1",
     "budo": "^8.2.2",
     "surge": "^0.18.0",
-    "uglify-js": "^2.6.2"
+    "uglify-es": "^3"
   },
   "scripts": {
     "test": "node test.js",