diff --git a/package.json b/package.json
index 8bca4f6..e488747 100644
--- a/package.json
+++ b/package.json
@@ -48,7 +48,7 @@
     "eslint": "^1.6.0",
     "eslint-config-standard": "^4.4.0",
     "eslint-plugin-standard": "^1.3.1",
-    "istanbul": "^0.3.22",
+    "istanbul": "^0.4.0",
     "mocha": "^2.0.1",
     "should": "^6.0.3",
     "should-http": "0.0.3",