diff --git a/gnu/system/install.scm b/gnu/system/install.scm
index 329c7aba32..734a361c37 100644
--- a/gnu/system/install.scm
+++ b/gnu/system/install.scm
@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
+;;; Copyright © 2016 Andreas Enge <andreas@enge.fr>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -392,6 +393,7 @@ (define installation-os
                      parted ddrescue
                      grub                  ;mostly so xrefs to its manual work
                      cryptsetup
+                     mdadm
                      btrfs-progs
                      wireless-tools iw wpa-supplicant-minimal iproute
                      ;; XXX: We used to have GNU fdisk here, but as of version