Django alterField doesn't keep NOT NULL when max_length changes

I am writing a django migration to change max_length to CharField in the following model from 200 to 255, but doing so changes those fields from non-nullable to nullable. I want these fields to remain non-null.

With sqlmigrate

I can see the sql that django runs for every migration:

Model definition

# -*- coding: utf-8 -*-

from django.db import models


class Account(models.Model):
    # Would be added by Django default anyways.
    id = models.AutoField(primary_key=True)

    name = models.CharField(max_length=200)
    email = models.EmailField(max_length=200)
    password = models.CharField(max_length=200)

    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    last_seen_at = models.DateTimeField(auto_now_add=True)

    project_token = models.CharField(max_length=200)
    url = models.URLField(max_length=200)
    notification_emails = models.TextField(blank=True)

      

        
        
        
      

    

Initial migration 0001

    BEGIN;
    CREATE TABLE `pnmodels_account` (`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY, `name` varchar(200) NOT NULL, `email` varchar(200) NOT NULL, `password` varchar(200) NOT NULL, `created_at` datetime NOT NULL, `updated_at` datetime NOT NULL, `last_seen_at` datetime NOT NULL, `project_token` varchar(200) NOT NULL, `url` varchar(200) NOT NULL, `notification_emails` longtext NOT NULL);

    COMMIT;

      

        
        
        
      

    

Migration 0002 to update max_length to 255

    BEGIN;
    ALTER TABLE `pnmodels_account` MODIFY `email` varchar(255);
    ALTER TABLE `pnmodels_account` MODIFY `name` varchar(255);
    ALTER TABLE `pnmodels_account` MODIFY `password` varchar(255);
    ALTER TABLE `pnmodels_account` MODIFY `project_token` varchar(255);
    ALTER TABLE `pnmodels_account` MODIFY `url` varchar(255);

    COMMIT;

      

        
        
        
      

    

I think MODIFY

0002 should be included NOT NULL

. Is this a django bug or am I missing something?

Usage: Django == 1.7.7, mysqlclient == 1.3.6