diff --git a/package.json b/package.json
index 217206e..25847c1 100644
--- a/package.json
+++ b/package.json
@@ -34,7 +34,7 @@
     "recast": "0"
   },
   "devDependencies": {
-    "istanbul": "^0.3.2",
+    "istanbul": "^0.4.2",
     "mocha": "^2.0.1"
   },
   "engines": {