diff --git a/Experimental-features.md b/Experimental-features.md
index 9719e34..721cd85 100644
--- a/Experimental-features.md
+++ b/Experimental-features.md
@@ -6,6 +6,8 @@ If something doesn't work as expected, I suggest you first disable _"Experimenta
 
 ### Privacy exposure reduction: local mirroring
 
+[**Important note:** local mirroring is currently know to break web fonts of these end up being locally cached: [issue #291](https://github.com/gorhill/uBlock/issues/291).]
+
 One way users increase their privacy exposure is through [content delivery networks](http://en.wikipedia.org/wiki/Content_delivery_network) ("CDN") and likes. Good examples of CDN are `ajax.googleapis.com`, `cdnjs.cloudflare.com`, `googletagservices.com`, etc. These servers are used to serve resources to countless web sites.
 
 When a resources is pulled from one of these CDNs, typically the [referrer header](http://en.wikipedia.org/wiki/HTTP_referer) is set in the HTTP request, which allows ubiquitous CDNs to collect data about your browsing habits. Not good for privacy.