diff --git a/package.json b/package.json
index 543b9cc..a01ee39 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,7 @@
     "async": "^1.4.2",
     "coveralls": "^2.11.4",
     "get-function-name": "0.0.1",
-    "istanbul": "^0.3.19",
+    "istanbul": "^0.4.0",
     "mocha": "^2.3.2",
     "mocha-lcov-reporter": "1.0.0"
   },