diff --git a/source/recipes/build/nixpkg/main.adoc0 b/source/recipes/build/nixpkg/main.adoc0
index f529e08..88ff13b 100644
--- a/source/recipes/build/nixpkg/main.adoc0
+++ b/source/recipes/build/nixpkg/main.adoc0
@@ -26,12 +26,19 @@ $ git add flake.lock
 $ git commit -a -m temp
 ////
 
-[source,nix,linenums,highlight='37..39,42']
+[source,nix,linenums,highlight='21..34']
 .flake.nix
 ....
 $# cat flake.nix
 ....
 
+We can build the flake to see how it modifies the script.
+
+....
+$ nix build
+$ cat result/bin/hello-cow
+....
+
 Here's the flake in action.
 
 ....