Sequelize TypeError: defineCall is not a function

Working on an express-generator project with Sequelize and SQLite.

I'm getting an Sequelize TypeError that I've been working on for hours but I'm coming up against a brick wall:

C:\-----\node_modules\sequelize\lib\sequelize.js:392 this.importCache[path] = defineCall(this, DataTypes); ^ TypeError: defineCall is not a function at Sequelize.import (C:\----\node_modules\sequelize\lib\sequelize.js:392:32) at C:\----\models\index.js:25:32

After doing some research, it appears that this could be caused when trying to import a non-sequelize object. Below is the problematic index.js file.

index.js start:

var Sequelize = require('sequelize');

var config = {
  dialect: 'sqlite',
  storage: 'library.db'
};

var connection = new Sequelize(config);
var contents = fs.readdirSync(__dirname);
var db = {};

I think the issue is in this snippet but I can't see it:

contents.forEach(function(file){
  var path = [__dirname, file].join('/');
  var model = connection.import(path);

  db[model.name] = model;
});

Object.keys(db).forEach(function(modelName){
  var model = db[modelName];

  if(model.associate) {
    model.associate(db);
  }
});


module.exports = {
  models: db,
  connection: connection
};

I do not have any function called defineCall, any idea where the error is coming from?