content-fade-in() mixin error

[OvidiuS]

When trying to use:

@include content-fade-in();

i get this error:

Base-level rules cannot contain the parent-selector-referencing character '&'. Backtrace: node_modules/sass-toolkit/stylesheets/toolkit/_fonts.scss:132, in mixin content-fade-in stdin:7 in E:\~work\Webpack-Start-Boilerplate\node_modules\sass-toolkit\stylesheets\toolkit\_fonts.scss (line 132, column 5)

Using sass-toolkit 2.10.0 with node-sass 3.10.0