diff --git a/package.json b/package.json
index ca0cd37c..7c2366cc 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,7 @@
   ],
   "devDependencies": {
     "buffer-from": "^1.1.1",
-    "express": "^4.15.3",
+    "express": "^5.0.0",
     "mocha": "^3.5.3",
     "nyc": "^17.1.0",
     "serve-static": "^1.12.3",