diff --git a/package.json b/package.json
index a95fd07..35bf0ae 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,7 @@
   "devDependencies": {
     "assume": "1.x.x",
     "istanbul": "0.x.x",
-    "mocha": "4.x.x",
+    "mocha": "^5.1.0",
     "pre-commit": "1.x.x"
   }
 }