diff --git a/nixos-modules/lib/make-ext2-fs.nix b/nixos-modules/lib/make-ext2-fs.nix
index 013f14d..7b6bd1a 100644
--- a/nixos-modules/lib/make-ext2-fs.nix
+++ b/nixos-modules/lib/make-ext2-fs.nix
@@ -43,7 +43,7 @@ in pkgs.stdenv.mkDerivation {
 
     truncate --size=$bytes $img
 
-    faketime -f "1970-01-01 00:00:01" fakeroot mkfs.ext2 -L NIXOS_GENODE -U ${config.genode.boot.storeFsUuid} -d ./rootImage $img
+    faketime -f "1970-01-01 00:00:01" fakeroot mkfs.ext2 -L NIXOS_GENODE -U ${config.block.partitions.store.guid} -d ./rootImage $img
 
     export EXT2FS_NO_MTAB_OK=yes
     # I have ended up with corrupted images sometimes, I suspect that