diff --git a/guix/packages.scm b/guix/packages.scm
index 5e8e3a4ff4..6e61e16aa4 100644
--- a/guix/packages.scm
+++ b/guix/packages.scm
@@ -718,11 +718,11 @@ (define (package-upstream-name* package)
     (or (assq-ref (package-properties package) 'upstream-name)
         (let loop ((prefixes namespaces))
           (match prefixes
-            ('() name)
+            (() name)
             ((prefix rest ...)
               (if (string-prefix? prefix name)
                 (substring name (string-length prefix))
-                (loop (cdr prefixes)))))))))
+                (loop rest))))))))
 
 (define (hidden-package p)
   "Return a \"hidden\" version of P--i.e., one that 'fold-packages' and thus,