diff --git a/conf/layer.conf b/conf/layer.conf
index 4177097..f65c1d3 100644
--- a/conf/layer.conf
+++ b/conf/layer.conf
@@ -8,7 +8,7 @@ BBFILE_COLLECTIONS += "mortsgna-layer"
 BBFILE_PATTERN_mortsgna-layer := "^${LAYERDIR}/"
 BBFILE_PRIORITY_mortsgna-layer = "7"
 
-LAYERSERIES_COMPAT_mortsgna-layer = "dunfell gatesgarth"
+LAYERSERIES_COMPAT_mortsgna-layer = "dunfell gatesgarth hardknott"
 
 # This is a compromise: Because of dynamic appends it needs oe-core only. Our
 # images have a huge dependency list (see README). So the layers set here are