diff --git a/nixos/lib/make-disk-image.nix b/nixos/lib/make-disk-image.nix
index bf32a36895c5..6fec322f9095 100644
--- a/nixos/lib/make-disk-image.nix
+++ b/nixos/lib/make-disk-image.nix
@@ -84,7 +84,7 @@ let format' = format; in let
   # FIXME: merge with channel.nix / make-channel.nix.
   channelSources = pkgs.runCommand "nixos-${config.system.nixos.version}" {} ''
     mkdir -p $out
-    cp -prd ${nixpkgs} $out/nixos
+    cp -prd ${nixpkgs.outPath} $out/nixos
     chmod -R u+w $out/nixos
     if [ ! -e $out/nixos/nixpkgs ]; then
       ln -s . $out/nixos/nixpkgs
diff --git a/nixos/modules/installer/cd-dvd/channel.nix b/nixos/modules/installer/cd-dvd/channel.nix
index 01cfe8a02e10..e946c4abc576 100644
--- a/nixos/modules/installer/cd-dvd/channel.nix
+++ b/nixos/modules/installer/cd-dvd/channel.nix
@@ -16,7 +16,7 @@ let
     { }
     ''
       mkdir -p $out
-      cp -prd ${nixpkgs} $out/nixos
+      cp -prd ${nixpkgs.outPath} $out/nixos
       chmod -R u+w $out/nixos
       if [ ! -e $out/nixos/nixpkgs ]; then
         ln -s . $out/nixos/nixpkgs