diff --git a/nixos/modules/system/boot/stage-1.nix b/nixos/modules/system/boot/stage-1.nix
index f58b68cb335..f4cf9753c0a 100644
--- a/nixos/modules/system/boot/stage-1.nix
+++ b/nixos/modules/system/boot/stage-1.nix
@@ -251,9 +251,9 @@ let
     postInstall = ''
       echo checking syntax
       # check both with bash
-      ${pkgs.bash}/bin/sh -n $target
+      ${pkgs.buildPackages.bash}/bin/sh -n $target
       # and with ash shell, just in case
-      ${extraUtils}/bin/ash -n $target
+      ${pkgs.buildPackages.busybox}/bin/ash -n $target
     '';
 
     inherit udevRules extraUtils modulesClosure;