diff --git a/package.json b/package.json
index d6c96b0..d2781b8 100644
--- a/package.json
+++ b/package.json
@@ -24,7 +24,7 @@
     "minifier": "0.8.1",
     "preprocessor": "1.4.0",
     "qunit": "0.9.3",
-    "uglify-js": "2.8.29"
+    "uglify-js": "3.9.4"
   },
   "scripts": {
     "test": "make test"