diff --git a/website/src/controllers/api-v3/challenges.js b/website/src/controllers/api-v3/challenges.js
index fa3a71b818..252ffe6c7e 100644
--- a/website/src/controllers/api-v3/challenges.js
+++ b/website/src/controllers/api-v3/challenges.js
@@ -30,12 +30,12 @@ api.createChallenge = {
   async handler (req, res) {
     let user = res.locals.user;
 
-    req.checkBody('group', res.t('groupIdRequired')).notEmpty();
+    req.checkBody('groupId', res.t('groupIdRequired')).notEmpty();
 
     let validationErrors = req.validationErrors();
     if (validationErrors) throw validationErrors;
 
-    let groupId = req.body.group;
+    let groupId = req.body.groupId;
     let prize = req.body.prize;
 
     let group = await Group.getGroup(user, groupId, '-chat');
@@ -107,7 +107,7 @@ api.getChallenges = {
     let challenges = await Challenge.find({
       $or: [
         {_id: {$in: user.challenges}}, // Challenges where the user is participating
-        {group: {$in: groups}}, // Challenges in groups where I'm a member
+        {groupId: {$in: groups}}, // Challenges in groups where I'm a member
         {leader: user._id}, // Challenges where I'm the leader
       ],
       _id: {$ne: '95533e05-1ff9-4e46-970b-d77219f199e9'}, // remove the Spread the Word Challenge for now, will revisit when we fix the closing-challenge bug TODO revisit
@@ -183,11 +183,11 @@ function _closeChal (challenge, broken = {}) {
       },
     }, {multi: true}).exec(),
     // Update the challengeCount on the group
-    Group.update({_id: challenge.group}, {$inc: {challengeCount: -1}}).exec(),
+    Group.update({_id: challenge.groupId}, {$inc: {challengeCount: -1}}).exec(),
   ];
 
   // Refund the leader if the challenge is closed and the group not the tavern
-  if (challenge.group !== 'habitrpg' && brokenReason === 'CHALLENGE_DELETED') {
+  if (challenge.groupId !== 'habitrpg' && brokenReason === 'CHALLENGE_DELETED') {
     tasks.push(User.update({_id: challenge.leader}, {$inc: {balance: challenge.prize / 4}}).exec());
   }
 
diff --git a/website/src/models/challenge.js b/website/src/models/challenge.js
index d5b3bf1a1b..00ab26a491 100644
--- a/website/src/models/challenge.js
+++ b/website/src/models/challenge.js
@@ -11,7 +11,7 @@ let schema = new Schema({
   name: {type: String, required: true},
   shortName: {type: String, required: true}, // TODO what is it?
   description: String,
-  official: {type: Boolean, default: false},
+  official: {type: Boolean, default: false}, // TODO only settable by admin
   tasksOrder: {
     habits: [{type: String, ref: 'Task'}],
     dailys: [{type: String, ref: 'Task'}],
@@ -19,14 +19,15 @@ let schema = new Schema({
     rewards: [{type: String, ref: 'Task'}],
   },
   leader: {type: String, ref: 'User', validate: [validator.isUUID, 'Invalid uuid.'], required: true},
-  group: {type: String, ref: 'Group', validate: [validator.isUUID, 'Invalid uuid.'], required: true},
-  timestamp: {type: Date, default: Date.now, required: true}, // TODO what is this? use timestamps from plugin?
+  groupId: {type: String, ref: 'Group', validate: [validator.isUUID, 'Invalid uuid.'], required: true},
+  timestamp: {type: Date, default: Date.now, required: true}, // TODO what is this? use timestamps from plugin? not settable?
   memberCount: {type: Number, default: 0},
-  prize: {type: Number, default: 0, min: 0},
+  challengeCount: {type: Number, default: 0},
+  prize: {type: Number, default: 0, min: 0}, // TODO no update?
 });
 
 schema.plugin(baseModel, {
-  noSet: ['_id', 'memberCount', 'tasksOrder'],
+  noSet: ['_id', 'memberCount', 'challengeCount', 'tasksOrder'],
 });