diff --git a/.travis.yml b/.travis.yml
index e0d921f..2129237 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: node_js
 node_js:
-- '4.3'
+- '4.6'
 after_success: "./node_modules/.bin/codecov"
 deploy:
   provider: npm
diff --git a/package.json b/package.json
index 6a34e52..c386e69 100644
--- a/package.json
+++ b/package.json
@@ -36,5 +36,8 @@
     "node-gcm": "^0.14.0",
     "npmlog": "^2.0.3",
     "parse": "^1.8.1"
+  },
+    "engines": {
+    "node": ">= 4.6.0"
   }
 }