diff --git a/package.json b/package.json
index c731899..ac3a760 100644
--- a/package.json
+++ b/package.json
@@ -32,7 +32,7 @@
     "tick-tock": "~1.0.0"
   },
   "devDependencies": {
-    "assume": "~2.1.0",
+    "assume": "~2.2.0",
     "istanbul": "~0.4.5",
     "mocha": "~3.5.0",
     "pre-commit": "~1.2.0"