diff --git a/package.json b/package.json
index 0c50ab3ca..3d0279644 100644
--- a/package.json
+++ b/package.json
@@ -62,7 +62,7 @@
     "eslint-config-google": "^0.7.1",
     "exorcist": "^0.4.0",
     "expect": "^1.20.2",
-    "istanbul": "^0.3.13",
+    "istanbul": "^0.4.5",
     "jsdoc": "^3.4.0",
     "lolex": "^1.5.2",
     "mocha": "^3.2.0",