diff --git a/nixos/modules/installer/cd-dvd/channel.nix b/nixos/modules/installer/cd-dvd/channel.nix
index ea7e3e16b8d..1e5e2b2615c 100644
--- a/nixos/modules/installer/cd-dvd/channel.nix
+++ b/nixos/modules/installer/cd-dvd/channel.nix
@@ -17,7 +17,9 @@ let
       mkdir -p $out
       cp -prd ${pkgs.path} $out/nixos
       chmod -R u+w $out/nixos
-      ln -s . $out/nixos/nixpkgs
+      if [ ! -e $out/nixos/nixpkgs ]; then
+        ln -s . $out/nixos/nixpkgs
+      fi
       rm -rf $out/nixos/.git
       echo -n ${config.system.nixosVersionSuffix} > $out/nixos/.version-suffix
     '';