diff --git a/common/models/user.js b/common/models/user.js
index 9f288d2514..f8af5ed45a 100644
--- a/common/models/user.js
+++ b/common/models/user.js
@@ -11,10 +11,14 @@ module.exports = function(User) {
   // set salt factor for passwords
   User.settings.saltWorkFactor = 5;
 
-  //User.validatesExclusionOf('username', {
-  //  inArray: blacklistedUsernames,
-  //  message: 'username is taken'
-  //});
+  // username should not be in blacklist
+  User.validatesExclusionOf('username', {
+    'in': blacklistedUsernames,
+    message: 'is taken'
+  });
+
+  // username should be unique
+  User.validatesUniquenessOf('username');
 
   debug('setting up user hooks');
   // send verification email to new camper
diff --git a/common/models/user.json b/common/models/user.json
index df99af1651..a7caad6227 100644
--- a/common/models/user.json
+++ b/common/models/user.json
@@ -44,7 +44,8 @@
     "username": {
       "type": "string",
       "lowercase": true,
-      "trim": true
+      "trim": true,
+      "require": true
     },
     "bio": {
       "type": "string",