diff --git a/package.json b/package.json
index 1974505..9bb1bc1 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
     "polyfill-ua": "^1.0.1"
   },
   "devDependencies": {
-    "istanbul": "0",
+    "istanbul": "0.4.2",
     "mocha": "2",
     "standardberry": "*"
   },