diff --git a/nixos/modules/system/boot/loader/grub/grub.nix b/nixos/modules/system/boot/loader/grub/grub.nix
index 449f58ae4dd..3c879450ba6 100644
--- a/nixos/modules/system/boot/loader/grub/grub.nix
+++ b/nixos/modules/system/boot/loader/grub/grub.nix
@@ -41,6 +41,7 @@ let
       grubEfi = f grubEfi;
       grubTargetEfi = if cfg.efiSupport && (cfg.version == 2) then f (grubEfi.grubTarget or "") else "";
       bootPath = args.path;
+      storePath = config.boot.loader.grub.storePath;
       bootloaderId = if args.efiBootloaderId == null then "NixOS${efiSysMountPoint'}" else args.efiBootloaderId;
       inherit efiSysMountPoint;
       inherit (args) devices;
@@ -180,6 +181,15 @@ in
         '';
       };
 
+      storePath = mkOption {
+        default = "/nix/store";
+        type = types.str;
+        description = ''
+          Path to the Nix store when looking for kernels at boot.
+          Only makes sense when copyKernels is false.
+        '';
+      };
+
       extraPrepareConfig = mkOption {
         default = "";
         type = types.lines;
diff --git a/nixos/modules/system/boot/loader/grub/install-grub.pl b/nixos/modules/system/boot/loader/grub/install-grub.pl
index 66d82e091d1..9db4c4003c9 100644
--- a/nixos/modules/system/boot/loader/grub/install-grub.pl
+++ b/nixos/modules/system/boot/loader/grub/install-grub.pl
@@ -55,6 +55,7 @@ my $fsIdentifier = get("fsIdentifier");
 my $grubEfi = get("grubEfi");
 my $grubTargetEfi = get("grubTargetEfi");
 my $bootPath = get("bootPath");
+my $storePath = get("storePath");
 my $canTouchEfiVariables = get("canTouchEfiVariables");
 my $efiSysMountPoint = get("efiSysMountPoint");
 my $gfxmodeEfi = get("gfxmodeEfi");
@@ -213,7 +214,7 @@ sub GrubFs {
 my $grubBoot = GrubFs($bootPath);
 my $grubStore;
 if ($copyKernels == 0) {
-    $grubStore = GrubFs("/nix/store");
+    $grubStore = GrubFs($storePath);
 }
 
 # Generate the header.
diff --git a/nixos/modules/system/boot/stage-1-init.sh b/nixos/modules/system/boot/stage-1-init.sh
index 5af644279e5..e8d276920a8 100644
--- a/nixos/modules/system/boot/stage-1-init.sh
+++ b/nixos/modules/system/boot/stage-1-init.sh
@@ -317,7 +317,7 @@ mountFS() {
 
 
 # Try to find and mount the root device.
-mkdir /mnt-root
+mkdir -p $targetRoot
 
 exec 3< @fsInfo@