diff --git a/README.md b/README.md
index 17421b8..3023293 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,8 @@
 json-bigint
 ===========
 
+[![Greenkeeper badge](https://badges.greenkeeper.io/sidorares/json-bigint.svg)](https://greenkeeper.io/)
+
 [![Build Status](https://secure.travis-ci.org/sidorares/json-bigint.png)](http://travis-ci.org/sidorares/json-bigint)
 [![NPM](https://nodei.co/npm/json-bigint.png?downloads=true&stars=true)](https://nodei.co/npm/json-bigint/)
 
diff --git a/package.json b/package.json
index 1e54d71..23e07f6 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
     "bignumber.js": "^4.0.0"
   },
   "devDependencies": {
-    "chai": "~1.9.1",
-    "mocha": "~1.20.1"
+    "chai": "~3.5.0",
+    "mocha": "~3.3.0"
   }
 }