diff --git a/.travis.yml b/.travis.yml
index 49a494f..225ead2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: node_js
 
-node_js: "8"
+node_js: "4"
 
 before_script:
   - npm run setup
diff --git a/package.json b/package.json
index c086df9..66dc9b3 100644
--- a/package.json
+++ b/package.json
@@ -13,6 +13,9 @@
     "build": "tsc --removeComments",
     "run": "node -r source-map-support/register example/testBot.js"
   },
+  "engines" : {
+    "node" : ">=6.0"
+  },
   "author": "CasperTech Ltd",
   "license": "MIT",
   "repository": {