Sass loader doesn't like it when you switch between syntax in the same file. Also for consistency it would be best to remove the semicolons here. https://github.com/couds/react-bulma-components/blob/master/src/components/heading/heading.sass#L1 https://github.com/couds/react-bulma-components/blob/master/src/components/heading/heading.sass#L2