diff --git a/test/api/v3/integration/tasks/PUT-tasks_challenge_challengeId.test.js b/test/api/v3/integration/tasks/PUT-tasks_challenge_challengeId.test.js
new file mode 100644
index 0000000000..99b368de00
--- /dev/null
+++ b/test/api/v3/integration/tasks/PUT-tasks_challenge_challengeId.test.js
@@ -0,0 +1,321 @@
+import {
+  generateUser,
+  generateGroup,
+  generateChallenge,
+  translate as t,
+} from '../../../../helpers/api-integration/v3';
+import { v4 as generateUUID } from 'uuid';
+
+describe('PUT /tasks/:id', () => {
+  let user;
+  let guild;
+  let challenge;
+
+  before(async () => {
+    user = await generateUser();
+    guild = await generateGroup(user);
+    challenge = await generateChallenge(user, guild);
+  });
+
+  context('errors', () => {
+    let task;
+
+    beforeEach(async () => {
+      task = await user.post(`/tasks/challenge/${challenge._id}`, {
+        text: 'test habit',
+        type: 'habit',
+      });
+    });
+
+    it('returns error when incorrect id is passed', async () => {
+      await expect(user.put(`/tasks/${generateUUID()}`, {
+        text: 'some new text',
+        up: false,
+        down: false,
+        notes: 'some new notes',
+      })).to.eventually.be.rejected.and.eql({
+        code: 404,
+        error: 'NotFound',
+        message: t('taskNotFound'),
+      });
+    });
+
+    it('returns error when user is not a member of the challenge', async () => {
+      let anotherUser = await generateUser();
+
+      await expect(anotherUser.put(`/tasks/${task._id}`, {
+        text: 'some new text',
+        up: false,
+        down: false,
+        notes: 'some new notes',
+      })).to.eventually.be.rejected.and.eql({
+        code: 401,
+        error: 'NotAuthorized',
+        message: t('onlyChalLeaderEditTasks'),
+      });
+    });
+  });
+
+  context('validates params', () => {
+    let task;
+
+    beforeEach(async () => {
+      task = await user.post(`/tasks/challenge/${challenge._id}`, {
+        text: 'test habit',
+        type: 'habit',
+      });
+    });
+
+    it(`ignores setting _id, type, userId, history, createdAt,
+                        updatedAt, challenge, completed, streak,
+                        dateCompleted fields`, async () => {
+      let savedTask = await user.put(`/tasks/${task._id}`, {
+        _id: 123,
+        type: 'daily',
+        userId: 123,
+        history: [123],
+        createdAt: 'yesterday',
+        updatedAt: 'tomorrow',
+        challenge: 'no',
+        completed: true,
+        streak: 25,
+        dateCompleted: 'never',
+      });
+
+      expect(savedTask._id).to.equal(task._id);
+      expect(savedTask.type).to.equal(task.type);
+      expect(savedTask.userId).to.equal(task.userId);
+      expect(savedTask.history).to.eql(task.history);
+      expect(savedTask.createdAt).to.equal(task.createdAt);
+      expect(savedTask.updatedAt).to.be.greaterThan(task.updatedAt);
+      expect(savedTask.challenge._id).to.equal(task.challenge._id);
+      expect(savedTask.completed).to.equal(task.completed);
+      expect(savedTask.streak).to.equal(task.streak);
+      expect(savedTask.dateCompleted).to.equal(task.dateCompleted);
+    });
+
+    it('ignores invalid fields', async () => {
+      let savedTask = await user.put(`/tasks/${task._id}`, {
+        notValid: true,
+      });
+
+      expect(savedTask.notValid).to.be.undefined;
+    });
+  });
+
+  context('habits', () => {
+    let habit;
+
+    beforeEach(async () => {
+      habit = await user.post(`/tasks/challenge/${challenge._id}`, {
+        text: 'test habit',
+        type: 'habit',
+        notes: 1976,
+      });
+    });
+
+    it('updates a habit', async () => {
+      let savedHabit = await user.put(`/tasks/${habit._id}`, {
+        text: 'some new text',
+        up: false,
+        down: false,
+        notes: 'some new notes',
+      });
+
+      expect(savedHabit.text).to.eql('some new text');
+      expect(savedHabit.notes).to.eql('some new notes');
+      expect(savedHabit.up).to.eql(false);
+      expect(savedHabit.down).to.eql(false);
+    });
+  });
+
+  context('todos', () => {
+    let todo;
+
+    beforeEach(async () => {
+      todo = await user.post(`/tasks/challenge/${challenge._id}`, {
+        text: 'test todo',
+        type: 'todo',
+        notes: 1976,
+      });
+    });
+
+    it('updates a todo', async () => {
+      let savedTodo = await user.put(`/tasks/${todo._id}`, {
+        text: 'some new text',
+        notes: 'some new notes',
+      });
+
+      expect(savedTodo.text).to.eql('some new text');
+      expect(savedTodo.notes).to.eql('some new notes');
+    });
+
+    it('can update checklists (replace it)', async () => {
+      await user.put(`/tasks/${todo._id}`, {
+        checklist: [
+          {text: 123, completed: false},
+          {text: 456, completed: true},
+        ],
+      });
+
+      let savedTodo = await user.put(`/tasks/${todo._id}`, {
+        checklist: [
+          {text: 789, completed: false},
+        ],
+      });
+
+      expect(savedTodo.checklist.length).to.equal(1);
+      expect(savedTodo.checklist[0].text).to.equal('789');
+      expect(savedTodo.checklist[0].completed).to.equal(false);
+    });
+
+    it('can update tags (replace them)', async () => {
+      let finalUUID = generateUUID();
+      await user.put(`/tasks/${todo._id}`, {
+        tags: [generateUUID(), generateUUID()],
+      });
+
+      let savedTodo = await user.put(`/tasks/${todo._id}`, {
+        tags: [finalUUID],
+      });
+
+      expect(savedTodo.tags.length).to.equal(1);
+      expect(savedTodo.tags[0]).to.equal(finalUUID);
+    });
+  });
+
+  context('dailys', () => {
+    let daily;
+
+    beforeEach(async () => {
+      daily = await user.post(`/tasks/challenge/${challenge._id}`, {
+        text: 'test daily',
+        type: 'daily',
+        notes: 1976,
+      });
+    });
+
+    it('updates a daily', async () => {
+      let savedDaily = await user.put(`/tasks/${daily._id}`, {
+        text: 'some new text',
+        notes: 'some new notes',
+        frequency: 'daily',
+        everyX: 5,
+      });
+
+      expect(savedDaily.text).to.eql('some new text');
+      expect(savedDaily.notes).to.eql('some new notes');
+      expect(savedDaily.frequency).to.eql('daily');
+      expect(savedDaily.everyX).to.eql(5);
+    });
+
+    it('can update checklists (replace it)', async () => {
+      await user.put(`/tasks/${daily._id}`, {
+        checklist: [
+          {text: 123, completed: false},
+          {text: 456, completed: true},
+        ],
+      });
+
+      let savedDaily = await user.put(`/tasks/${daily._id}`, {
+        checklist: [
+          {text: 789, completed: false},
+        ],
+      });
+
+      expect(savedDaily.checklist.length).to.equal(1);
+      expect(savedDaily.checklist[0].text).to.equal('789');
+      expect(savedDaily.checklist[0].completed).to.equal(false);
+    });
+
+    it('can update tags (replace them)', async () => {
+      let finalUUID = generateUUID();
+      await user.put(`/tasks/${daily._id}`, {
+        tags: [generateUUID(), generateUUID()],
+      });
+
+      let savedDaily = await user.put(`/tasks/${daily._id}`, {
+        tags: [finalUUID],
+      });
+
+      expect(savedDaily.tags.length).to.equal(1);
+      expect(savedDaily.tags[0]).to.equal(finalUUID);
+    });
+
+    it('updates repeat, even if frequency is set to daily', async () => {
+      await user.put(`/tasks/${daily._id}`, {
+        frequency: 'daily',
+      });
+
+      let savedDaily = await user.put(`/tasks/${daily._id}`, {
+        repeat: {
+          m: false,
+          su: false,
+        },
+      });
+
+      expect(savedDaily.repeat).to.eql({
+        m: false,
+        t: true,
+        w: true,
+        th: true,
+        f: true,
+        s: true,
+        su: false,
+      });
+    });
+
+    it('updates everyX, even if frequency is set to weekly', async () => {
+      await user.put(`/tasks/${daily._id}`, {
+        frequency: 'weekly',
+      });
+
+      let savedDaily = await user.put(`/tasks/${daily._id}`, {
+        everyX: 5,
+      });
+
+      expect(savedDaily.everyX).to.eql(5);
+    });
+
+    it('defaults startDate to today if none date object is passed in', async () => {
+      let savedDaily = await user.put(`/tasks/${daily._id}`, {
+        frequency: 'weekly',
+      });
+
+      expect((new Date(savedDaily.startDate)).getDay()).to.eql((new Date()).getDay());
+    });
+  });
+
+  context('rewards', () => {
+    let reward;
+
+    beforeEach(async () => {
+      reward = await user.post(`/tasks/challenge/${challenge._id}`, {
+        text: 'test reward',
+        type: 'reward',
+        notes: 1976,
+        value: 10,
+      });
+    });
+
+    it('updates a reward', async () => {
+      let savedReward = await user.put(`/tasks/${reward._id}`, {
+        text: 'some new text',
+        notes: 'some new notes',
+        value: 10,
+      });
+
+      expect(savedReward.text).to.eql('some new text');
+      expect(savedReward.notes).to.eql('some new notes');
+      expect(savedReward.value).to.eql(10);
+    });
+
+    it('requires value to be coerced into a number', async () => {
+      let savedReward = await user.put(`/tasks/${reward._id}`, {
+        value: '100',
+      });
+
+      expect(savedReward.value).to.eql(100);
+    });
+  });
+});
diff --git a/website/src/controllers/api-v3/tasks.js b/website/src/controllers/api-v3/tasks.js
index fcb95bd3d7..7402618d65 100644
--- a/website/src/controllers/api-v3/tasks.js
+++ b/website/src/controllers/api-v3/tasks.js
@@ -301,7 +301,7 @@ api.updateTask = {
     if (!task) {
       throw new NotFound(res.t('taskNotFound'));
     } else if (!task.userId) { // If the task belongs to a challenge make sure the user has rights
-      challenge = await Challenge.find().selec({_id: task.challenge.id}).select('leader').exec();
+      challenge = await Challenge.findOne({_id: task.challenge.id}).exec();
       if (!challenge) throw new NotFound(res.t('challengeNotFound'));
       if (challenge.leader !== user._id) throw new NotAuthorized(res.t('onlyChalLeaderEditTasks'));
     } else if (task.userId !== user._id) { // If the task is owned by an user make it's the current one
@@ -326,8 +326,8 @@ api.updateTask = {
       delete req.body.tags;
     }
 
-    // TODO we have to convert task to an object because otherwise thigns doesn't get merged correctly, bad for performances?
-    // TODO regarding comment above make sure other models with nested fields are using this trick too
+    // TODO we have to convert task to an object because otherwise things don't get merged correctly. Bad for performances?
+    // TODO regarding comment above, make sure other models with nested fields are using this trick too
     _.assign(task, _.merge(task.toObject(), Tasks.Task.sanitizeUpdate(req.body)));
     // TODO console.log(task.modifiedPaths(), task.toObject().repeat === tep)
     // repeat is always among modifiedPaths because mongoose changes the other of the keys when using .toObject()