diff --git a/README.org b/README.org
index dc13104..3237b2d 100644
--- a/README.org
+++ b/README.org
@@ -101,6 +101,9 @@ nonfree Linux kernel and nonfree firmware with the following command:
 guix system image --image-type=iso9660 /path/to/this/channel/nongnu/system/install.scm
 #+end_src
 
+Make sure you have added nonguix as a channel, and run =guix pull= then =hash guix=
+to refresh your terminal environment.
+
 Like the official Guix installation image, this will produce a read-only image
 with any changes made stored in memory.  As indicated below, you will need to
 run ~guix pull~ to download the Nonguix package descriptions, so will need