diff --git a/package.json b/package.json
index 5e73084..aec308a 100644
--- a/package.json
+++ b/package.json
@@ -32,7 +32,7 @@
   },
   "homepage": "https://github.com/3rd-Eden/env-variable",
   "devDependencies": {
-    "assume": "^2.0.1",
+    "assume": "^2.2.0",
     "mocha": "^5.1.1",
     "istanbul": "^0.4.5"
   }