diff --git a/package.json b/package.json
index c7b066f..a17b4a4 100644
--- a/package.json
+++ b/package.json
@@ -33,7 +33,7 @@
     "extendible": "0.1.x"
   },
   "devDependencies": {
-    "assume": "~1.4.1",
+    "assume": "~1.5.0",
     "istanbul": "~0.4.5",
     "mocha": "~3.1.2",
     "pre-commit": "~1.2.0"