diff --git a/invenio_theme_tugraz/assets/semantic-ui/less/invenio_theme_tugraz/theme.less b/invenio_theme_tugraz/assets/semantic-ui/less/invenio_theme_tugraz/theme.less
index dae2560..0ad4ef5 100644
--- a/invenio_theme_tugraz/assets/semantic-ui/less/invenio_theme_tugraz/theme.less
+++ b/invenio_theme_tugraz/assets/semantic-ui/less/invenio_theme_tugraz/theme.less
@@ -9,7 +9,8 @@
 @import "header";
 @import "footer";
 @import "overrides";
-@import url("https://fonts.googleapis.com/css?family=Source+Sans+Pro&display=swap");
+@import (css)
+  url("https://fonts.googleapis.com/css?family=Source+Sans+Pro&display=swap");
 
 /***
 **TODO: