diff --git a/package.json b/package.json
index b466e76..a10c23b 100644
--- a/package.json
+++ b/package.json
@@ -45,7 +45,7 @@
     "express": "^4.12.0",
     "istanbul": "^0.4.0",
     "mocha": "3.4.2",
-    "sinon": "^4.0.0"
+    "sinon": "^6.0.1"
   },
   "peerDependencies": {
     "express": "^4.12.0"