diff --git a/nixos/doc/manual/preface.xml b/nixos/doc/manual/preface.xml
index e9cb3b08e084..6ac9ae7e7861 100644
--- a/nixos/doc/manual/preface.xml
+++ b/nixos/doc/manual/preface.xml
@@ -5,7 +5,15 @@
  <para>
   This manual describes how to install, use and extend NixOS, a Linux
   distribution based on the purely functional package management system
-  <link xlink:href="https://nixos.org/nix">Nix</link>.
+  <link xlink:href="https://nixos.org/nix">Nix</link>, that is composed
+  using modules and packages defined in the
+  <link xlink:href="https://nixos.org/nixpkgs">Nixpkgs</link> project.
+ </para>
+ <para>
+  Additional information regarding the Nix package manager and the Nixpkgs
+  project can be found in respectively the
+  <link xlink:href="https://nixos.org/nix/manual">Nix manual</link> and the
+  <link xlink:href="https://nixos.org/nixpkgs/manual">Nixpkgs manual</link>.
  </para>
  <para>
   If you encounter problems, please report them on the