diff --git a/package.json b/package.json
index ee69b0f..68a8311 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,7 @@
   },
   "devDependencies": {
     "after": "0.8.1",
-    "istanbul": "0.3.9",
+    "istanbul": "0.3.15",
     "mocha": "2.2.5",
     "supertest": "1.0.1"
   },