--- PG-4.4-orig/generic/proof-site.el
+++ PG-4.4/generic/proof-site.el
@@ -127,7 +127,7 @@
   :group 'proof-general-internals)
 
 (defcustom proof-images-directory
-  (concat proof-home-directory "images/")
+  "@SITEETC@/images/"
     "Where Proof General image files are installed.  Ends with slash."
   :type 'directory
   :group 'proof-general-internals)