__inject__ is not a function

[BENSIMON Raphaël]

Hi, it's my first time i use vue-style-loader and i got this error

_styles_components_FormGroup_css__WEBPACK_IMPORTED_MODULE_1___default.a.__inject__ is not a function

This is my code

import FormGroup from './components/formGroup/FormGroup.vue'
import FormGroupStyle from './styles/components/FormGroup.css'
export default  {
	install(Vue, options) {
		Vue.mixin({
			beforeCreate() {
				console.log(FormGroupStyle.__inject__)
				FormGroupStyle.__inject__(this.$ssrContext)
			}
		})
		Vue.component('lv-form-group', FormGroup)
	}
}