如何避免django“与相关的m2m字段冲突”错误？

class Voteable(models.Model):
    likes_balance = models.IntegerField(default=0,editable=False)
    votes = models.ManyToManyField(User,blank=True,editable=False)
    likes = models.ManyToManyField(User,editable=False)

    class Meta:
        abstract = True

class Item(Voteable):
    title = models.CharField(max_length=20,db_index=True)
    description = models.TextField(max_length=1000)
    contact_user = models.ForeignKey(User,null=True,blank=True)

    class Meta:
        abstract = True

class Movie(Item):
    cover = models.ImageField(upload_to='images/covers/')

class Car(Item):
    seller = models.CharField(max_length=50)

当我尝试使用“python manage.py syncdb”创建表时,我收到错误消息：

m2m字段的访问者’喜欢’与相关字段’User.movi??e_set’的冲突.将related_name参数添加到“likes”的定义中.

因为我在Item类中有更多的字段,所以不想将它们全部复制到所有子类,只是设置像错误建议的related_name.

有什么建议怎么处理吗？