diff --git a/README b/README
index 7dd016ef80..3e9e9722ac 100644
--- a/README
+++ b/README
@@ -22,6 +22,7 @@ GNU Guix currently depends on the following packages:
 
   - [[http://gnu.org/software/guile/][GNU Guile 2.0.x]], version 2.0.5 or later
   - [[http://gnupg.org/][GNU libgcrypt]]
+  - optionally [[http://savannah.nongnu.org/projects/guile-json/][Guile-JSON]], for the 'guix import pypi' command
 
 Unless `--disable-daemon' was passed, the following packages are needed:
 
diff --git a/doc/guix.texi b/doc/guix.texi
index f6357bdaec..ac2aad643c 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -150,7 +150,12 @@ GNU Guix depends on the following packages:
 
 @itemize
 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.0.5 or later;
-@item @url{http://gnupg.org/, GNU libgcrypt}
+@item @url{http://gnupg.org/, GNU libgcrypt};
+@item
+optionally, installing
+@url{http://savannah.nongnu.org/projects/guile-json/, Guile-JSON} will
+allow you to use the @command{guix import pypi} command; it is of
+interest primarily for developers and not for casual users.
 @end itemize
 
 Unless @code{--disable-daemon} was passed to @command{configure}, the