diff --git a/package.json b/package.json
index 55c5797..b6cd21f 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
   "devDependencies": {
     "chai": "~1.8.1",
     "coveralls": "~2.6.0",
-    "istanbul": "~0.1.46",
+    "istanbul": "~0.4.2",
     "mocha": "~1.14.0",
     "mocha-lcov-reporter": "0.0.1",
     "moment-ranger": "0.1.4"