diff --git a/package.json b/package.json
index f42a2079b..b3f2fcae6 100644
--- a/package.json
+++ b/package.json
@@ -73,7 +73,7 @@
     "opener": "~1.4.0",
     "optimist": "0.6.x",
     "portfinder": "^1.0.13",
-    "union": "~0.4.3"
+    "union": "~0.5.0"
   },
   "devDependencies": {
     "common-style": "^3.0.0",