diff --git a/installer/nixos-install.nix b/installer/nixos-install.nix
index 8e3eff4d947a..298bf594c446 100644
--- a/installer/nixos-install.nix
+++ b/installer/nixos-install.nix
@@ -1,4 +1,4 @@
-{ stdenv, perl, runCommand, substituteAll, nix
+{ perl, runCommand, substituteAll, nix
 , # URL of the Nixpkgs distribution that the installer will pull.
   # Leave empty for a pure source distribution.
   nixpkgsURL ? ""
diff --git a/installer/nixos-rebuild.nix b/installer/nixos-rebuild.nix
new file mode 100644
index 000000000000..52cc939eabfd
--- /dev/null
+++ b/installer/nixos-rebuild.nix
@@ -0,0 +1,9 @@
+{substituteAll, nix}:
+
+substituteAll {
+  name = "nixos-rebuild";
+  src = ./nixos-rebuild.sh;
+  dir = "bin";
+  isExecutable = true;
+  inherit nix;
+}
diff --git a/installer/nixos-rebuild.sh b/installer/nixos-rebuild.sh
new file mode 100644
index 000000000000..12404f8d4af2
--- /dev/null
+++ b/installer/nixos-rebuild.sh
@@ -0,0 +1,49 @@
+#! @shell@ -e
+
+
+# What are we supposed to do?
+action="$1"
+
+if test -z "$action"; then
+    # !!! more or less cut&paste from
+    # system/switch-to-configuration.sh (which we call, of course).
+    cat <<EOF
+Usage: $0 [switch|boot|test|build]
+
+switch: make the configuration the boot default and activate now
+boot:   make the configuration the boot default
+test:   activate the configuration, but don't make it the boot default
+build:  build the configuration, but don't make it the default or
+        activate it
+EOF
+    exit 1
+fi
+
+
+# Allow the location of NixOS sources and the system configuration
+# file to be overridden.
+if test -z "$NIXOS"; then NIXOS=/etc/nixos/nixos; fi
+if test -z "$NIXOS_CONFIG"; then NIXOS_CONFIG=/etc/nixos/configuration.nix; fi
+
+
+# Either upgrade the configuration in the system profile (for "switch"
+# or "boot"), or just build it and create a symlink "result" in the
+# current directory (for "build" and "test").
+if test "$action" = "switch" -o "$action" = "boot"; then
+    nix-env -p /nix/var/nix/profiles/system -f $NIXOS/system/system.nix \
+        --arg configuration "import $NIXOS_CONFIG" \
+        --set -A system
+    pathToConfig=/nix/var/nix/profiles/system
+else
+    nix-build $NIXOS/system/system.nix \
+        --arg configuration "import $NIXOS_CONFIG" \
+        -A system -K -k
+    pathToConfig=./result
+fi
+
+
+# If we're not just building, then make the new configuration the boot
+# default and/or activate it now.
+if test "$action" = "switch" -o "$action" = "boot" -o "$action" = "test"; then
+    $pathToConfig/bin/switch-to-configuration "$action"
+fi
diff --git a/system/system.nix b/system/system.nix
index 58b638ea463b..1b5069b014ab 100644
--- a/system/system.nix
+++ b/system/system.nix
@@ -111,11 +111,16 @@ rec {
 
   # The installer.
   nixosInstall = import ../installer/nixos-install.nix {
-    inherit (pkgs) stdenv perl runCommand substituteAll;
+    inherit (pkgs) perl runCommand substituteAll;
     inherit nix;
     nixpkgsURL = config.get ["installer" "nixpkgsURL"];
   };
 
+  nixosRebuild = import ../installer/nixos-rebuild.nix {
+    inherit (pkgs) substituteAll;
+    inherit nix;
+  };
+
 
   # NSS modules.  Hacky!
   nssModules =
@@ -186,6 +191,7 @@ rec {
 #    pkgs.vim
     nix
     nixosInstall
+    nixosRebuild
     setuidWrapper
   ];
 
diff --git a/test.sh b/test.sh
deleted file mode 100755
index 6ea5e055aa6f..000000000000
--- a/test.sh
+++ /dev/null
@@ -1,9 +0,0 @@
-#! /bin/sh -e
-
-if test -z "$NIXOS"; then NIXOS=/etc/nixos/nixos; fi
-if test -z "$NIXOS_CONFIG"; then NIXOS_CONFIG=/etc/nixos/configuration.nix; fi
-
-nix-build $NIXOS/system/system.nix \
-    --arg configuration "import $NIXOS_CONFIG" \
-    -A system -K -k
-./result/bin/switch-to-configuration test
diff --git a/upgrade.sh b/upgrade.sh
deleted file mode 100755
index 5fb563871582..000000000000
--- a/upgrade.sh
+++ /dev/null
@@ -1,9 +0,0 @@
-#! /bin/sh -e
-
-if test -z "$NIXOS"; then NIXOS=/etc/nixos/nixos; fi
-if test -z "$NIXOS_CONFIG"; then NIXOS_CONFIG=/etc/nixos/configuration.nix; fi
-
-nix-env -p /nix/var/nix/profiles/system -f $NIXOS/system/system.nix \
-    --arg configuration "import $NIXOS_CONFIG" \
-    --set -A system
-/nix/var/nix/profiles/system/bin/switch-to-configuration switch