diff --git a/test/api/v3/integration/tasks/POST-tasks.test.js b/test/api/v3/integration/tasks/POST-tasks.test.js
index c8b9e9a37a..51999bc8a2 100644
--- a/test/api/v3/integration/tasks/POST-tasks.test.js
+++ b/test/api/v3/integration/tasks/POST-tasks.test.js
@@ -54,6 +54,21 @@ describe('POST /tasks', () => {
       });
     });
 
+    it('does not update user.tasksOrder.{taskType} when the task is not saved because invalid', async () => {
+      let originalHabitsOrder = (await user.get('/user')).tasksOrder.habits;
+      return expect(user.post('/tasks', {
+        type: 'habit',
+      })).to.eventually.be.rejected.and.eql({ // this block is necessary
+        code: 400,
+        error: 'BadRequest',
+        message: 'habit validation failed',
+      }).then(async () => {
+        let updatedHabitsOrder = (await user.get('/user')).tasksOrder.habits;
+
+        expect(updatedHabitsOrder).to.eql(originalHabitsOrder);
+      });
+    });
+
     it('automatically sets "task.userId" to user\'s uuid', async () => {
       let task = await user.post('/tasks', {
         text: 'test habit',
diff --git a/website/src/controllers/api-v3/tasks.js b/website/src/controllers/api-v3/tasks.js
index 25b5245a04..84ccf0a221 100644
--- a/website/src/controllers/api-v3/tasks.js
+++ b/website/src/controllers/api-v3/tasks.js
@@ -32,16 +32,28 @@ api.createTask = {
     let user = res.locals.user;
 
     let toSave = tasksData.map(taskData => {
+      // Validate that task.type is valid
       if (!taskData || Tasks.tasksTypes.indexOf(taskData.type) === -1) throw new BadRequest(res.t('invalidTaskType'));
 
       let taskType = taskData.type;
       let newTask = new Tasks[taskType](Tasks.Task.sanitizeCreate(taskData));
       newTask.userId = user._id;
+
+      // Validate that the task is valid and throw if it isn't
+      // otherwise since we're saving user and task in parallel it could save the user with a tasksOrder that doens't match reality
+      let validationErrors = newTask.validateSync();
+      if (validationErrors) throw validationErrors;
+
+      // Otherwise update the user
       user.tasksOrder[`${taskType}s`].unshift(newTask._id);
 
-      return newTask.save();
+      return newTask;
     });
 
+    // If all tasks are valid, save everything, withough running validation again
+    toSave = toSave.map(task => task.save({
+      validateBeforeSave: false,
+    }));
     toSave.unshift(user.save());
     let results = await Q.all(toSave);