diff --git a/gnu/services/desktop.scm b/gnu/services/desktop.scm
index e4f0736b899d0a491f4dbccd888c9ad46391e196..02bcf1b19fe22b2060bc84e04f6678fb8d7aa2f1 100644
--- a/gnu/services/desktop.scm
+++ b/gnu/services/desktop.scm
@@ -378,7 +378,7 @@ (define (polkit-directory packages)
 (define polkit-etc-files
   (match-lambda
     (($ <polkit-configuration> polkit packages)
-     `(("polkit-1" ,(polkit-directory packages))))))
+     `(("polkit-1" ,(polkit-directory (cons polkit packages)))))))
 
 (define polkit-setuid-programs
   (match-lambda