unexpected token

[RafaelC457ro]

I using stylor in my project but a got this issue

node_modules/stylord/lib/stylord.js (40:6)
38:   const modules = styles.reduce(
39:     (previous, current) => ({
40:       ...previous,
          ^
41:       [current.componentName]: current.className
42:     }),

I fix this adding

buble({
      objectAssign: 'Object.assign'
    }),

to my rollup.config.js, any way to use this without need this plugin?