diff --git a/nixos/modules/virtualisation/amazon-grow-partition.nix b/nixos/modules/virtualisation/amazon-grow-partition.nix
deleted file mode 100644
index 69b80d900ba..00000000000
--- a/nixos/modules/virtualisation/amazon-grow-partition.nix
+++ /dev/null
@@ -1,24 +0,0 @@
-# This module automatically grows the root partition on Amazon EC2 HVM
-# instances. This allows an instance to be created with a bigger root
-# filesystem than provided by the AMI.
-
-{ config, lib, pkgs, ... }:
-
-{
-  config = lib.mkIf config.ec2.hvm {
-    boot.initrd.extraUtilsCommands = ''
-      copy_bin_and_libs ${pkgs.gawk}/bin/gawk
-      copy_bin_and_libs ${pkgs.gnused}/bin/sed
-      copy_bin_and_libs ${pkgs.utillinux}/sbin/sfdisk
-      cp -v ${pkgs.cloud-utils}/bin/growpart $out/bin/growpart
-      ln -s sed $out/bin/gnused
-    '';
-
-    boot.initrd.postDeviceCommands = ''
-      if [ -e /dev/xvda ] && [ -e /dev/xvda1 ]; then
-        TMPDIR=/run sh $(type -P growpart) /dev/xvda 1
-        udevadm settle
-      fi
-    '';
-  };
-}
diff --git a/nixos/modules/virtualisation/amazon-image.nix b/nixos/modules/virtualisation/amazon-image.nix
index ebf398fa266..f9c3f2e53ad 100644
--- a/nixos/modules/virtualisation/amazon-image.nix
+++ b/nixos/modules/virtualisation/amazon-image.nix
@@ -11,10 +11,12 @@ with lib;
 let cfg = config.ec2; in
 
 {
-  imports = [ ../profiles/headless.nix ./ec2-data.nix ./amazon-grow-partition.nix ./amazon-init.nix ];
+  imports = [ ../profiles/headless.nix ./ec2-data.nix ./grow-partition.nix ./amazon-init.nix ];
 
   config = {
 
+    virtualisation.growPartition = cfg.hvm;
+
     fileSystems."/" = {
       device = "/dev/disk/by-label/nixos";
       autoResize = true;
diff --git a/nixos/modules/virtualisation/grow-partition.nix b/nixos/modules/virtualisation/grow-partition.nix
new file mode 100644
index 00000000000..34547905166
--- /dev/null
+++ b/nixos/modules/virtualisation/grow-partition.nix
@@ -0,0 +1,41 @@
+# This module automatically grows the root partition on virtual machines.
+# This allows an instance to be created with a bigger root filesystem
+# than provided by the machine image.
+
+{ config, lib, pkgs, ... }:
+
+{
+
+  options = {
+
+    virtualisation.growPartition = mkOption {
+      type = types.bool;
+      default = true;
+    };
+
+  };
+
+  config = mkIf config.virtualisation.growPartition {
+
+    boot.initrd.extraUtilsCommands = ''
+      copy_bin_and_libs ${pkgs.gawk}/bin/gawk
+      copy_bin_and_libs ${pkgs.gnused}/bin/sed
+      copy_bin_and_libs ${pkgs.utillinux}/sbin/sfdisk
+      copy_bin_and_libs ${pkgs.utillinux}/sbin/lsblk
+      cp -v ${pkgs.cloud-utils}/bin/growpart $out/bin/growpart
+      ln -s sed $out/bin/gnused
+    '';
+
+    boot.initrd.postDeviceCommands = ''
+      rootDevice="${config.fileSystems."/".device}"
+      if [ -e "$rootDevice" ]; then
+        rootDevice="$(readlink -f "$rootDevice")"
+        parentDevice="$(lsblk -npo PKNAME "$rootDevice")"
+        TMPDIR=/run sh $(type -P growpart) "$parentDevice" "''${rootDevice#$parentDevice}"
+        udevadm settle
+      fi
+    '';
+
+  };
+
+}
diff --git a/nixos/modules/virtualisation/virtualbox-image.nix b/nixos/modules/virtualisation/virtualbox-image.nix
index 3a598a1c7dc..b6a5b3e4788 100644
--- a/nixos/modules/virtualisation/virtualbox-image.nix
+++ b/nixos/modules/virtualisation/virtualbox-image.nix
@@ -8,6 +8,8 @@ let
 
 in {
 
+  imports = [ ./grow-partition.nix ];
+
   options = {
     virtualbox = {
       baseImageSize = mkOption {
@@ -64,7 +66,10 @@ in {
         '';
     };
 
-    fileSystems."/".device = "/dev/disk/by-label/nixos";
+    fileSystems."/" = {
+      device = "/dev/disk/by-label/nixos";
+      autoResize = true;
+    };
 
     boot.loader.grub.device = "/dev/sda";