diff --git a/lib/schema.js b/lib/schema.js
index eeced1d..33a1cbe 100644
--- a/lib/schema.js
+++ b/lib/schema.js
@@ -160,11 +160,11 @@ Schema.types.binarySet = function () {
 };
 
 Schema.types.uuid = function () {
-  return Joi.string().guid().default(nodeUUID.v4);
+  return Joi.string().guid().default(nodeUUID.v4());
 };
 
 Schema.types.timeUUID = function () {
-  return Joi.string().guid().default(nodeUUID.v1);
+  return Joi.string().guid().default(nodeUUID.v1());
 };
 
 Schema.prototype.validate = function (params, options) {