diff --git a/models/site.rb b/models/site.rb
index 5380d9a4..5ff4cf3b 100644
--- a/models/site.rb
+++ b/models/site.rb
@@ -33,10 +33,11 @@ class Site < Sequel::Model
     application/rss+xml
     application/x-elc
     image/webp
+    image/x-xcf
   }
 
   VALID_EXTENSIONS = %w{
-    html htm txt text css js jpg jpeg png gif svg md markdown eot ttf woff woff2 json geojson csv tsv mf ico pdf asc key pgp xml mid midi manifest otf webapp less sass rss kml dae obj mtl scss webp
+    html htm txt text css js jpg jpeg png gif svg md markdown eot ttf woff woff2 json geojson csv tsv mf ico pdf asc key pgp xml mid midi manifest otf webapp less sass rss kml dae obj mtl scss webp xcf
   }
 
   VALID_EDITABLE_EXTENSIONS = %w{