TypeError: engine.compileFile is not a function

[tuananh]

I'm using koa2 with koa-views

app.use(convert(views(__dirname + '/app/views', {
    map: {
        html: 'jade'
    }
})))

app.use(async (ctx, next) => {
    ctx.render = co.wrap(ctx.render.bind(ctx))
    await next()
})

I'm getting this error TypeError: engine.compileFile is not a function when browse to the url. Could someone help me figure what went wrong here?