diff --git a/doc/guix.texi b/doc/guix.texi
index 979288c3be..c5a7de7c3b 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -4321,7 +4321,9 @@ guix import gem rails
 
 @item cpan
 @cindex CPAN
-Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
+Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}@footnote{This
+functionality requires Guile-JSON to be installed.
+@xref{Requirements}.}.
 Information is taken from the JSON-formatted metadata provided through
 @uref{https://api.metacpan.org/, MetaCPAN's API} and includes most
 relevant information, such as module dependencies.  License information