sequelize: Association between tables in different DBs ignored

I have two tables. They belong to different databases.

export default db1.define(`hero`, {
teamId: {
    type: Sequelize.INTEGER
    ....
},
name; {
    type: Sequelize.STRING
}
....
}

export default db2.define(`team`, {
id: {
    type: Sequelize.INTEGER
},
name; {
    type: Sequelize.STRING
}
....
}

Then in another file, I associate hero with team like this in another file.

import Hero
import Team
Hero.hasOne(Team, {foreignKey: 'teamId'})

Now it is telling me that "ER_NO_SUCH_TABLE: Table 'db1.team' doesn't exist". It seems to be ignoring my db specification. Is this normal? And how should I counteract this? It should be trying to associate db1.hero with db2.team. Thanks.

Dialect: mysql __Database version: 5.6.31 __Sequelize version: ^3.14.2