diff --git a/package.json b/package.json
index 835fe0a..64baaf8 100644
--- a/package.json
+++ b/package.json
@@ -52,7 +52,7 @@
     "rollup": "^0.59.0",
     "rollup-plugin-commonjs": "^9.1.2",
     "rollup-plugin-node-resolve": "^3.0.1",
-    "rollup-plugin-uglify": "^3.0.0",
+    "rollup-plugin-uglify": "^4.0.0",
     "rollup-watch": "^4.3.1",
     "selenium-assistant": "^5.3.0",
     "wait-on": "^2.1.0"