diff --git a/README.adoc b/README.adoc
index 4e10aeb..c999cc9 100644
--- a/README.adoc
+++ b/README.adoc
@@ -14868,7 +14868,8 @@ but note that this does not include script specific options.
 You don't need to depend on GitHub:
 
 ....
-sudo apt install asciidoctor
+sudo apt-get install rubygems
+sudo gem install asciidoctor -v 2.0.10
 ./build-doc
 xdg-open out/README.html
 ....