diff --git a/installer/nixos-checkout.sh b/installer/nixos-checkout.sh
index a1defc3f1ce..b4767d292e1 100644
--- a/installer/nixos-checkout.sh
+++ b/installer/nixos-checkout.sh
@@ -21,9 +21,14 @@ if test -e nixpkgs -a ! -e nixpkgs/.svn; then
     mv nixpkgs nixpkgs-$backupTimestamp
 fi
 
+if test -e nixos/services -a ! -e nixos/services/.svn; then
+    mv nixos/services services-$backupTimestamp
+fi
+
 # Check out the NixOS and Nixpkgs sources.
 svn co https://svn.cs.uu.nl:12443/repos/trace/nixos/trunk nixos
 svn co https://svn.cs.uu.nl:12443/repos/trace/nixpkgs/trunk nixpkgs
+svn co https://svn.cs.uu.nl:12443/repos/trace/services/trunk nixos/services
 
 # A few symlink.
 ln -sfn ../nixpkgs/pkgs nixos/pkgs