diff --git a/nixos/modules/tasks/filesystems.nix b/nixos/modules/tasks/filesystems.nix
index 3f553948d78d..91e30aa4c0af 100644
--- a/nixos/modules/tasks/filesystems.nix
+++ b/nixos/modules/tasks/filesystems.nix
@@ -187,7 +187,7 @@ let
       skipCheck = fs: fs.noCheck || fs.device == "none" || builtins.elem fs.fsType fsToSkipCheck || isBindMount fs;
       # https://wiki.archlinux.org/index.php/fstab#Filepath_spaces
       escape = string: builtins.replaceStrings [ " " "\t" ] [ "\\040" "\\011" ] string;
-    in fstabFileSystems: { rootPrefix ? "" }: concatMapStrings (fs:
+    in fstabFileSystems: { }: concatMapStrings (fs:
       (if fs.device != null then escape fs.device
          else if fs.label != null then "/dev/disk/by-label/${escape fs.label}"
          else throw "No device specified for mount point ‘${fs.mountPoint}’.")
@@ -198,9 +198,7 @@ let
       + "\n"
     ) fstabFileSystems;
 
-    initrdFstab = pkgs.writeText "initrd-fstab" (makeFstabEntries (filter utils.fsNeededForBoot fileSystems) {
-      rootPrefix = "/sysroot";
-    });
+    initrdFstab = pkgs.writeText "initrd-fstab" (makeFstabEntries (filter utils.fsNeededForBoot fileSystems) { });
 
 in