diff --git a/nixos/tests/initrd-luks-empty-passphrase.nix b/nixos/tests/initrd-luks-empty-passphrase.nix
index d2805f2f173..521456e7e0b 100644
--- a/nixos/tests/initrd-luks-empty-passphrase.nix
+++ b/nixos/tests/initrd-luks-empty-passphrase.nix
@@ -18,6 +18,11 @@ in {
       emptyDiskImages = [ 512 ];
       useBootLoader = true;
       useEFIBoot = true;
+      # This requires to have access
+      # to a host Nix store as
+      # the new root device is /dev/vdb
+      # an empty 512MiB drive, containing no Nix store.
+      mountHostNixStore = true;
     };
 
     boot.loader.systemd-boot.enable = true;