diff --git a/etc/settings b/etc/settings
--- a/etc/settings
+++ b/etc/settings
@@ -1,9 +1,11 @@
 # -*- shell-script -*- :mode=shellscript:
 
 AFP_BASE="$COMPONENT"
 AFP="$AFP_BASE/thys"
 
+isabelle_directory '$AFP_BASE'
+isabelle_directory '$AFP'
+
 AFP_BUILD_OPTIONS='-v -o browser_info -o "document=pdf" -o "document_variants=document:outline=/proof,/ML"'
 
 ISABELLE_TOOLS="$ISABELLE_TOOLS:$AFP_BASE/tools"
-