diff --git a/modules/services/x11/xserver/default.nix b/modules/services/x11/xserver/default.nix
index acaea17649c..3e49420778e 100644
--- a/modules/services/x11/xserver/default.nix
+++ b/modules/services/x11/xserver/default.nix
@@ -277,6 +277,15 @@ let
       };
 
     };
+
+    environment.x11Packages = mkOption {
+      default = [];
+      type = types.list types.packages;
+      description = "
+        List of packages added to the system when the xserver is
+        activated. (<option>services.xserver.enable</option>).
+      ";
+    };
   };
 in
 
@@ -505,7 +514,7 @@ mkIf cfg.enable {
       }
     ];
 
-    extraPackages = [
+    x11Packages = [
       xorg.xrandr
       xorg.xrdb
       xorg.setxkbmap
@@ -514,6 +523,8 @@ mkIf cfg.enable {
     ++ optional (videoDriver == "nvidia") [
       kernelPackages.nvidia_x11
     ];
+
+    extraPackages = config.environment.x11Packages;
   };
 
   services = {
diff --git a/modules/services/x11/xserver/desktop-managers/default.nix b/modules/services/x11/xserver/desktop-managers/default.nix
index 3de3fa25792..c40266f99d7 100644
--- a/modules/services/x11/xserver/desktop-managers/default.nix
+++ b/modules/services/x11/xserver/desktop-managers/default.nix
@@ -2,7 +2,8 @@
 
 let
   inherit (pkgs.lib) mkOption mergeOneOption mkIf filter optionalString any;
-  cfg = config.services.xserver.desktopManager;
+  xcfg = config.services.xserver;
+  cfg = xcfg.desktopManager;
 
   # Whether desktop manager `d' is capable of setting a background.
   # If it isn't, the `feh' program is used as a fallback.
@@ -69,7 +70,7 @@ in
     };
   };
 
-  environment = mkIf (config.services.xserver.enable && cfg.session.needBGPackages) {
-    extraPackages = [ pkgs.feh ];
+  environment = mkIf cfg.session.needBGPackages {
+    x11Packages = [ pkgs.feh ];
   };
 }
diff --git a/modules/services/x11/xserver/desktop-managers/gnome.nix b/modules/services/x11/xserver/desktop-managers/gnome.nix
index d6fa064ef11..3fa82bae2ba 100644
--- a/modules/services/x11/xserver/desktop-managers/gnome.nix
+++ b/modules/services/x11/xserver/desktop-managers/gnome.nix
@@ -38,7 +38,7 @@ mkIf cfg.enable {
   };
 
   environment = {
-    extraPackages = [
+    x11Packages = [
       gnome.gnometerminal
       gnome.GConf
       gnome.gconfeditor
diff --git a/modules/services/x11/xserver/desktop-managers/kde-environment.nix b/modules/services/x11/xserver/desktop-managers/kde-environment.nix
index 5d9ab3ae5a3..3a4b8b22d36 100644
--- a/modules/services/x11/xserver/desktop-managers/kde-environment.nix
+++ b/modules/services/x11/xserver/desktop-managers/kde-environment.nix
@@ -1,7 +1,7 @@
 {pkgs, config, ...}:
 
 let
-  inherit (pkgs.lib) mkOption mkIf;
+  inherit (pkgs.lib) mkOption mkIf types;
   kdePackages = config.environment.kdePackages;
 
   options = {
@@ -25,6 +25,7 @@ let
       kdePackages = mkOption {
         default = [];
         example = [ pkgs.kde42.kdegames ];
+        type = types.list types.packages;
         description = ''
           Additional KDE packages to be used when you use KDE as a desktop
           manager.  By default, you only get the KDE base packages.
@@ -36,11 +37,11 @@ let
   };
 in
 
-mkIf (kdePackages != []) {
+mkIf (kdePackages != [] && config.services.xserver.enable) {
   require = options;
 
   environment = {
-    extraPackages = kdePackages;
+    x11Packages = kdePackages;
 
     shellInit = ''
       export KDEDIRS="${pkgs.lib.concatStringsSep ":" kdePackages}"
diff --git a/modules/services/x11/xserver/desktop-managers/kde.nix b/modules/services/x11/xserver/desktop-managers/kde.nix
index f8fb9f534f5..45c4c464f9a 100644
--- a/modules/services/x11/xserver/desktop-managers/kde.nix
+++ b/modules/services/x11/xserver/desktop-managers/kde.nix
@@ -2,8 +2,9 @@
 
 let
   inherit (pkgs.lib) mkOption mkIf;
-  cfg = config.services.xserver.desktopManager.kde;
-  xorg = config.services.xserver.package;
+  xcfg = config.services.xserver;
+  cfg = xcfg.desktopManager.kde;
+  xorg = xcfg.package;
 
   options = { services = { xserver = { desktopManager = {
 
@@ -18,7 +19,7 @@ let
   }; }; }; };
 in
 
-mkIf cfg.enable {
+mkIf (xcfg.enable && cfg.enable) {
   require = [
     options
 
@@ -63,7 +64,7 @@ mkIf cfg.enable {
       pkgs.kdebase
     ];
 
-    extraPackages = [
+    x11Packages = [
       xorg.xset # used by startkde, non-essential
     ];
 
diff --git a/modules/services/x11/xserver/desktop-managers/kde4.nix b/modules/services/x11/xserver/desktop-managers/kde4.nix
index 78cf90e33e4..f8b66e2840d 100644
--- a/modules/services/x11/xserver/desktop-managers/kde4.nix
+++ b/modules/services/x11/xserver/desktop-managers/kde4.nix
@@ -2,8 +2,9 @@
 
 let
   inherit (pkgs.lib) mkOption mkIf;
-  cfg = config.services.xserver.desktopManager.kde4;
-  xorg = config.services.xserver.package;
+  xcfg = config.services.xserver;
+  cfg = xcfg.desktopManager.kde4;
+  xorg = xcfg.package;
 
   options = { services = { xserver = { desktopManager = {
 
@@ -18,7 +19,7 @@ let
   }; }; }; };
 in
 
-mkIf cfg.enable {
+mkIf (xcfg.enable && cfg.enable) {
   require = [
     options
 
@@ -57,7 +58,7 @@ mkIf cfg.enable {
       pkgs.shared_mime_info
     ];
 
-    extraPackages = [
+    x11Packages = [
       xorg.xmessage # so that startkde can show error messages
       pkgs.qt4 # needed for qdbus
       xorg.xset # used by startkde, non-essential
diff --git a/modules/services/x11/xserver/desktop-managers/xterm.nix b/modules/services/x11/xserver/desktop-managers/xterm.nix
index 861d5001478..8524c0c6544 100644
--- a/modules/services/x11/xserver/desktop-managers/xterm.nix
+++ b/modules/services/x11/xserver/desktop-managers/xterm.nix
@@ -17,7 +17,7 @@ let
   
 in
 
-mkIf (config.services.xserver.enable && cfg.enable) {
+mkIf cfg.enable {
   require = options;
 
   services = {
@@ -37,7 +37,7 @@ mkIf (config.services.xserver.enable && cfg.enable) {
   };
 
   environment = {
-    extraPackages = [
+    x11Packages = [
       pkgs.xterm
     ];
   };
diff --git a/modules/services/x11/xserver/window-managers/compiz.nix b/modules/services/x11/xserver/window-managers/compiz.nix
index e99c3adb5b4..bf159582663 100644
--- a/modules/services/x11/xserver/window-managers/compiz.nix
+++ b/modules/services/x11/xserver/window-managers/compiz.nix
@@ -59,6 +59,6 @@ mkIf cfg.enable {
   };
 
   environment = {
-    extraPackages = [ pkgs.compiz ];
+    x11Packages = [ pkgs.compiz ];
   };
 }
diff --git a/modules/services/x11/xserver/window-managers/kwm.nix b/modules/services/x11/xserver/window-managers/kwm.nix
index db8696c510d..3d946f213a3 100644
--- a/modules/services/x11/xserver/window-managers/kwm.nix
+++ b/modules/services/x11/xserver/window-managers/kwm.nix
@@ -38,7 +38,7 @@ mkIf cfg.enable {
   };
 
   environment = {
-    extraPackages = [
+    x11Packages = [
       pkgs.kdelibs
       pkgs.kdebase
     ];
diff --git a/modules/services/x11/xserver/window-managers/metacity.nix b/modules/services/x11/xserver/window-managers/metacity.nix
index dc1ff911d65..ea1dd5a3bde 100644
--- a/modules/services/x11/xserver/window-managers/metacity.nix
+++ b/modules/services/x11/xserver/window-managers/metacity.nix
@@ -44,6 +44,6 @@ mkIf cfg.enable {
   };
 
   environment = {
-    extraPackages = [ gnome.metacity ];
+    x11Packages = [ gnome.metacity ];
   };
 }
diff --git a/modules/services/x11/xserver/window-managers/twm.nix b/modules/services/x11/xserver/window-managers/twm.nix
index f26be48776c..9dc3bea8093 100644
--- a/modules/services/x11/xserver/window-managers/twm.nix
+++ b/modules/services/x11/xserver/window-managers/twm.nix
@@ -39,6 +39,6 @@ mkIf cfg.enable {
   };
 
   environment = {
-    extraPackages = [ xorg.twm ];
+    x11Packages = [ xorg.twm ];
   };
 }
diff --git a/modules/services/x11/xserver/window-managers/wmii.nix b/modules/services/x11/xserver/window-managers/wmii.nix
index 191e31af1de..d1ff72092f1 100644
--- a/modules/services/x11/xserver/window-managers/wmii.nix
+++ b/modules/services/x11/xserver/window-managers/wmii.nix
@@ -47,7 +47,7 @@ mkIf cfg.enable {
   };
 
   environment = {
-    extraPackages = [
+    x11Packages = [
       pkgs.wmiiSnap
     ];
   };